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Bianca E, Dotti F, Orrico F, Ferri A. Thermoregulation of feet in cold environments: A study on alpinism. APPLIED ERGONOMICS 2024; 116:104205. [PMID: 38091693 DOI: 10.1016/j.apergo.2023.104205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 11/20/2023] [Accepted: 12/07/2023] [Indexed: 01/16/2024]
Abstract
Thermal comfort plays a crucial role in the performance and well-being of mountaineers, especially in extreme environments. The aim of this study was to develop a reliable protocol to assess the thermal comfort of mountaineering boots, with a specific focus on temperature variations in different regions of the foot and their correlation with physiological factors. Two different models of mountaineering boots were tested at two different environmental temperature (-15°C and -30°C). The mean skin temperature, measured according to International Standards BS EN ISO 9886:2004, was used as an indicator of overall thermal comfort. Physiological factors such as heart rate (HR), body mass index (BMI) and body surface area (BSA) were also measured to understand their relationship to thermoregulation. Kruskal-Wallis and Pearson's ProductMoment correlation tests were performed to investigate whether there was a statistically significant relationship. The results showed significant differences in foot temperature among the Testers, indicating variations in the perception of thermal comfort. The correlation analysis showed a strong positive relationship between mean skin temperature and HR, highlighting the influence of physiological factors on thermal comfort. In addition, the analysis showed that the dorsum and hallux areas had the largest temperature variations, suggesting the occurrence of vasoconstriction and potential discomfort. This study represents a preliminary approach to establishing a reliable protocol for assessing the thermal performance of cold protective footwear.
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Affiliation(s)
- Eleonora Bianca
- Department of Applied Science and Technology, Polytechnic of Turin, Turin, 10129, Italy.
| | - Francesca Dotti
- Department of Applied Science and Technology, Polytechnic of Turin, Turin, 10129, Italy.
| | | | - Ada Ferri
- Department of Applied Science and Technology, Polytechnic of Turin, Turin, 10129, Italy.
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Joshi A, Li R, Wu Y, Zhang M, Song G. Analysis of glove local microclimate properties for various glove types and fits using 3D scanning method. Heliyon 2024; 10:e23596. [PMID: 38205334 PMCID: PMC10777371 DOI: 10.1016/j.heliyon.2023.e23596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/28/2023] [Accepted: 12/07/2023] [Indexed: 01/12/2024] Open
Abstract
Due to their geometry and thermal physiology, hands are most vulnerable to cold weather injuries and loss of dexterity. Gloves are the most common for hand protection during exposure to extreme thermal and hazardous environments. Although glove microclimate properties such as area factor, air gap thickness, and contact area play a significant role in thermal protection, identifying local (at individual hand segments) glove microclimate properties is still a research gap. For the first time, the glove-microclimate properties for 16 hand segments at high spatial resolution were analyzed by employing state-of-the-art hand-held 3D scanner and post-processing techniques for different glove types. Our results clearly indicate that the glove area factor for distal phalanges is significantly higher (by 49.8 %) than that for other hand segments, which increases the heat transfer from distal phalanges. In contrast, average air gap thickness was relatively uniform across all hand segments. The glove type had a pronounced effect on glove microclimate properties, e.g., bulky and heavy cold weather protective gloves had a larger average air gap thickness and glove area factor. Regression models are also developed to estimate the glove microclimate properties from simple measurement (i.e., ease allowance). Overall, this study provides essential information for the design and development of protective gloves that can help improve safety, comfort, and dexterity. Methods and mathematical models developed in this study also contribute to facilitating extremity (e.g., hand) focused thermoregulation modeling, hazard simulation, injury prediction, ergonomic design, optimum performance (dexterity and tactility) along with thermal protection.
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Affiliation(s)
| | - Rui Li
- Iowa State University, Ames, IA, 50010, USA
| | - Yulin Wu
- Iowa State University, Ames, IA, 50010, USA
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 4: evolution, thermal adaptation and unsupported theories of thermoregulation. Eur J Appl Physiol 2024; 124:147-218. [PMID: 37796290 DOI: 10.1007/s00421-023-05262-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/13/2023] [Indexed: 10/06/2023]
Abstract
This review is the final contribution to a four-part, historical series on human exercise physiology in thermally stressful conditions. The series opened with reminders of the principles governing heat exchange and an overview of our contemporary understanding of thermoregulation (Part 1). We then reviewed the development of physiological measurements (Part 2) used to reveal the autonomic processes at work during heat and cold stresses. Next, we re-examined thermal-stress tolerance and intolerance, and critiqued the indices of thermal stress and strain (Part 3). Herein, we describe the evolutionary steps that endowed humans with a unique potential to tolerate endurance activity in the heat, and we examine how those attributes can be enhanced during thermal adaptation. The first of our ancestors to qualify as an athlete was Homo erectus, who were hairless, sweating specialists with eccrine sweat glands covering almost their entire body surface. Homo sapiens were skilful behavioural thermoregulators, which preserved their resource-wasteful, autonomic thermoeffectors (shivering and sweating) for more stressful encounters. Following emigration, they regularly experienced heat and cold stress, to which they acclimatised and developed less powerful (habituated) effector responses when those stresses were re-encountered. We critique hypotheses that linked thermoregulatory differences to ancestry. By exploring short-term heat and cold acclimation, we reveal sweat hypersecretion and powerful shivering to be protective, transitional stages en route to more complete thermal adaptation (habituation). To conclude this historical series, we examine some of the concepts and hypotheses of thermoregulation during exercise that did not withstand the tests of time.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise. Eur J Appl Physiol 2024; 124:1-145. [PMID: 37796292 DOI: 10.1007/s00421-023-05276-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 10/06/2023]
Abstract
In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 2: physiological measurements. Eur J Appl Physiol 2023; 123:2587-2685. [PMID: 37796291 DOI: 10.1007/s00421-023-05284-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/14/2023] [Indexed: 10/06/2023]
Abstract
In this, the second of four historical reviews on human thermoregulation during exercise, we examine the research techniques developed by our forebears. We emphasise calorimetry and thermometry, and measurements of vasomotor and sudomotor function. Since its first human use (1899), direct calorimetry has provided the foundation for modern respirometric methods for quantifying metabolic rate, and remains the most precise index of whole-body heat exchange and storage. Its alternative, biophysical modelling, relies upon many, often dubious assumptions. Thermometry, used for >300 y to assess deep-body temperatures, provides only an instantaneous snapshot of the thermal status of tissues in contact with any thermometer. Seemingly unbeknownst to some, thermal time delays at some surrogate sites preclude valid measurements during non-steady state conditions. To assess cutaneous blood flow, immersion plethysmography was introduced (1875), followed by strain-gauge plethysmography (1949) and then laser-Doppler velocimetry (1964). Those techniques allow only local flow measurements, which may not reflect whole-body blood flows. Sudomotor function has been estimated from body-mass losses since the 1600s, but using mass losses to assess evaporation rates requires precise measures of non-evaporated sweat, which are rarely obtained. Hygrometric methods provide data for local sweat rates, but not local evaporation rates, and most local sweat rates cannot be extrapolated to reflect whole-body sweating. The objective of these methodological overviews and critiques is to provide a deeper understanding of how modern measurement techniques were developed, their underlying assumptions, and the strengths and weaknesses of the measurements used for humans exercising and working in thermally challenging conditions.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- College of Human Ecology, Research Institute of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation. Eur J Appl Physiol 2023; 123:2379-2459. [PMID: 37702789 DOI: 10.1007/s00421-023-05272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/30/2023] [Indexed: 09/14/2023]
Abstract
This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Blasco Mariño R, Roy S, Martin Orejas M, Soteras Martínez I, Paal P. Ample room for cognitive bias in diagnosing accidental hypothermia. Diagnosis (Berl) 2023; 10:322-324. [PMID: 37014191 DOI: 10.1515/dx-2023-0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/20/2023] [Indexed: 04/05/2023]
Affiliation(s)
- Robert Blasco Mariño
- Department of Anesthesiology, Vall d'Hebron University Hospital, Barcelona, Spain
- Department of Medical Science, Faculty of Medicine, University of Girona, Barcelona, Spain
| | - Steven Roy
- Department of Critical Care Medicine, University of Calgary, Calgary, Canada
- O'Brien Institute for Public Health, University of Calgary, Calgary, Canada
| | - Maria Martin Orejas
- Department of Anesthesiology, Vall d'Hebron University Hospital, Barcelona, Spain
| | - Iñigo Soteras Martínez
- Department of Medical Science, Faculty of Medicine, University of Girona, Barcelona, Spain
- Department of Emergency, Cerdanya Hospital, Puigcerdà, Spain
- Sistema Emergencies Mèdiques (SEM), Hospitalet de Llobregat, Spain
| | - Peter Paal
- Department of Anaesthesiology and Intensive Care Medicine, St. John of God Hospital, Paracelsus Medical University, Salzburg, Austria
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Kazune S, Vasiljevs E, Caica-Rinca A, Marcinkevics Z, Grabovskis A. Infrared Thermography Imaging for Assessment of Peripheral Perfusion in Patients with Septic Shock. Bioengineering (Basel) 2023; 10:729. [PMID: 37370660 DOI: 10.3390/bioengineering10060729] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Skin temperature changes can be used to assess peripheral perfusion in circulatory shock patients. However, research has been limited to point measurements from acral parts of the body. Infrared thermography allows non-invasive evaluation of temperature distribution over a larger surface. Our study aimed to map thermographic patterns in the knee and upper thigh of 81 septic shock patients within 24 h of admission and determine the relationship between skin temperature patterns, mottling, and 28-day mortality. We extracted skin temperature measurements from zones corresponding to mottling scores and used a linear mixed model to analyze the distribution of skin temperature in patients with different mottling scores. Our results showed that the distribution of skin temperature in the anterior thigh and knee is physiologically heterogeneous and has no significant association with mottling or survival at 28 days. However, overall skin temperature of the anterior thigh and knee is significantly lower in non-survivors when modified by mottling score. No differences were found in skin temperature between the survivor and non-survivor groups. Our study shows the potential usefulness of infrared thermography in evaluating skin temperature patterns in resuscitated septic shock patients. Overall skin temperature of the anterior thigh and knee may be an important indicator of survival status when modified by mottling score.
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Affiliation(s)
- Sigita Kazune
- Department of Anesthesiology, Riga Stradins University, LV-1007 Riga, Latvia
- Laboratory of Biophotonics, Institute of Atomic Physics and Spectroscopy, University of Latvia, LV-1004 Riga, Latvia
| | - Edgars Vasiljevs
- Residency Development Department, University of Latvia, LV-1004 Riga, Latvia
| | - Anastasija Caica-Rinca
- Laboratory of Biophotonics, Institute of Atomic Physics and Spectroscopy, University of Latvia, LV-1004 Riga, Latvia
- Department of Human and Animal Physiology, Faculty of Biology, University of Latvia, LV-1004 Riga, Latvia
| | - Zbignevs Marcinkevics
- Laboratory of Biophotonics, Institute of Atomic Physics and Spectroscopy, University of Latvia, LV-1004 Riga, Latvia
- Department of Human and Animal Physiology, Faculty of Biology, University of Latvia, LV-1004 Riga, Latvia
| | - Andris Grabovskis
- Department of Human and Animal Physiology, Faculty of Biology, University of Latvia, LV-1004 Riga, Latvia
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Detert H, Karlernäs A, Rubensson C, Nyman E, Tesselaar E, Farnebo S. Microcirculatory response to cold stress test in the healthy hand. Microvasc Res 2023; 148:104540. [PMID: 37087099 DOI: 10.1016/j.mvr.2023.104540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/17/2023] [Accepted: 04/17/2023] [Indexed: 04/24/2023]
Abstract
OBJECTIVE Cold sensitivity of the fingers is common in several conditions. It has been linked to digital vasospasm, microvascular dysfunction, and neural mechanisms. This study aimed to investigate the normal digital microvascular response to a cold stress test in healthy individuals using Laser Speckle Contrast Imaging (LSCI). METHODS Twenty-six healthy individuals, mean age 31 (SD 9) years were included. Skin perfusion of digits II-V was measured using Laser Speckle Contrast Imaging before and after a standardized cold stress test. Changes in skin perfusion from baseline were analyzed between hands, digits, and sexes. RESULTS Skin perfusion was significantly (p < 0.0001) affected by cold provocation in both the cold exposed and the contralateral hands in all participants of the study. This effect was significantly different between the radial (digit II and III) and the ulnar (digit V) side of the hands (p < 0.001). There was a trend towards a larger decrease in perfusion in men (ns), and a faster recovery to baseline values in women (ns). A larger inter subject variability was seen in perfusion values in women. CONCLUSIONS The normal microvascular response to cold provocation may involve both centrally and regionally mediated processes. When exposing one hand to a cold stress test, the contralateral hand responds with simultaneous but smaller decreases in perfusion.
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Affiliation(s)
- Hedvig Detert
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden.
| | - Astrid Karlernäs
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Carin Rubensson
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Erika Nyman
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Medical Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden; Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
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Raef HS, Rebeiz L, Leaf RK, Hughes O, Jiang P, ElSeht A, Anderson KE, Wheeden K, Kochevar I, Elmariah SB, Dickey AK. Light-Related Cutaneous Symptoms of Erythropoietic Protoporphyria and Associations With Light Sensitivity Measurements. JAMA Dermatol 2023; 159:204-208. [PMID: 36630131 PMCID: PMC9857840 DOI: 10.1001/jamadermatol.2022.5850] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 11/08/2022] [Indexed: 01/12/2023]
Abstract
Importance Erythropoietic protoporphyria (EPP) is a rare and underdiagnosed genetic disease characterized by painful sensitivity to light. A better understanding and characterization of its light-induced cutaneous symptoms may aid in the identification of EPP in patients. Objectives To describe the cutaneous symptoms of erythropoietic protoporphyria (EPP) and to determine if these symptoms are associated with the degree of light sensitivity. Design, Setting, and Participants This was a cross-sectional study of adolescent and adult (≥15 years) patients with EPP across the US conducted by a single academic hospital via a remotely administered survey, measurements of light sensitivity by light dosimetry and by text message symptom assessments. Data analyses were conducted from November 2020 to April 2022. Exposures Sunlight exposure. Main Outcomes and Measures Self-reported symptoms and association with measured light sensitivity. Results The study sample consisted of 35 patients with EPP (mean [SD] age, 39.1 (15.5) years; 21 [60%] female; 14 [40%] male; 35 [100%] White individuals). The patients' median [range] skin tone was 3.0 (1.0-8.0), based on self-reporting from 1 (lightest) to 12 (darkest). A total of 24 participants completed the light dosimeter measurements. Phototoxic reactions were characterized by pain (97%; 34 patients), burning (97%; 34), tingling (97%; 34), pruritus (83%; 29), allodynia (89%; 31), improvement of symptoms with cold (89%; 31), achiness (24%; 12), fatigue (46%; 16), mild swelling (83%; 29), severe swelling (63%; 22), erythema (51%; 18), petechiae (40%; 14), skin cracking (43%; 15), scabbing (46%; 16), scarring (66%; 23), and other chronic skin changes (40%; 14). Patients with EPP reported that their hands, feet, and face were most sensitive to light and that their shoulders and legs were least sensitive; 25.7% (9 patient) reported no chronic skin changes, and 5.7% (2 patients) reported never having had any visible symptoms. None of these findings varied with the degree of light sensitivity except that lower overall light sensitivity was associated with lower ranked sensitivity of the neck and arms. Conclusions and Relevance The findings of this cross-sectional study suggest that patients with EPP have distinctive cutaneous symptoms that may aid in identification of this underdiagnosed disease. Characteristic EPP symptoms include light-induced cutaneous burning pain and occasional swelling, particularly over the hands, with a prodrome of pruritus and paresthesias. Minimal skin changes or the absence of visible skin changes during reactions to light, including lack of erythema, do not exclude an EPP diagnosis nor suggest low EPP disease burden.
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Affiliation(s)
- Haya S. Raef
- Department of Medicine, Massachusetts General Hospital, Boston
- Department of Dermatology, Massachusetts General Hospital, Boston
| | - Lina Rebeiz
- Department of Medicine, Massachusetts General Hospital, Boston
| | - Rebecca Karp Leaf
- Department of Medicine, Massachusetts General Hospital, Boston
- Harvard Medical School, Boston, Massachusetts
| | - Olivia Hughes
- Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts
| | - Paul Jiang
- Department of Medicine, Massachusetts General Hospital, Boston
| | - Abrahim ElSeht
- Department of Medicine, Massachusetts General Hospital, Boston
| | - Karl E. Anderson
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston
| | | | - Irene Kochevar
- Department of Dermatology, Massachusetts General Hospital, Boston
- Harvard Medical School, Boston, Massachusetts
| | - Sarina B. Elmariah
- Department of Dermatology, Massachusetts General Hospital, Boston
- Harvard Medical School, Boston, Massachusetts
| | - Amy K. Dickey
- Department of Medicine, Massachusetts General Hospital, Boston
- Harvard Medical School, Boston, Massachusetts
- Healthcare Transformation Lab, Massachusetts General Hospital, Boston
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11
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Geng YJ, Smolensky M, Sum-Ping O, Hermida R, Castriotta RJ. Circadian rhythms of risk factors and management in atherosclerotic and hypertensive vascular disease: Modern chronobiological perspectives of an ancient disease. Chronobiol Int 2023; 40:33-62. [PMID: 35758140 PMCID: PMC10355310 DOI: 10.1080/07420528.2022.2080557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 12/13/2022]
Abstract
Atherosclerosis, a chronic inflammatory disease of the arteries that appears to have been as prevalent in ancient as in modern civilizations, is predisposing to life-threatening and life-ending cardiac and vascular complications, such as myocardial and cerebral infarctions. The pathogenesis of atherosclerosis involves intima plaque buildup caused by vascular endothelial dysfunction, cholesterol deposition, smooth muscle proliferation, inflammatory cell infiltration and connective tissue accumulation. Hypertension is an independent and controllable risk factor for atherosclerotic cardiovascular disease (CVD). Conversely, atherosclerosis hardens the arterial wall and raises arterial blood pressure. Many CVD patients experience both atherosclerosis and hypertension and are prescribed medications to concurrently mitigate the two disease conditions. A substantial number of publications document that many pathophysiological changes caused by atherosclerosis and hypertension occur in a manner dependent upon circadian clocks or clock gene products. This article reviews progress in the research of circadian regulation of vascular cell function, inflammation, hemostasis and atherothrombosis. In particular, it delineates the relationship of circadian organization with signal transduction and activation of the renin-angiotensin-aldosterone system as well as disturbance of the sleep/wake circadian rhythm, as exemplified by shift work, metabolic syndromes and obstructive sleep apnea (OSA), as promoters and mechanisms of atherogenesis and risk for non-fatal and fatal CVD outcomes. This article additionally updates advances in the clinical management of key biological processes of atherosclerosis to optimally achieve suppression of atherogenesis through chronotherapeutic control of atherogenic/hypertensive pathological sequelae.
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Affiliation(s)
- Yong-Jian Geng
- The Center for Cardiovascular Biology and Atherosclerosis Research, Division of Cardiovascular Medicine, Department of Internal Medicine, McGovern School of Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Michael Smolensky
- The Center for Cardiovascular Biology and Atherosclerosis Research, Division of Cardiovascular Medicine, Department of Internal Medicine, McGovern School of Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Department of Biomedical Engineering, Cockrell School of Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Oliver Sum-Ping
- The Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Sciences, School of Medicine, Stanford University, Stanford, CA, USA
| | - Ramon Hermida
- Bioengineering & Chronobiology Laboratories, Atlantic Research Center for Telecommunication Technologies (atlanTTic), University of Vigo, Vigo, Spain
| | - Richard J. Castriotta
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Keck Medical School, University of Southern California, Los Angeles, CA, USA
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12
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Kuklane K, Eggeling J, Kemmeren M, Heus R. A Database of Static Thermal Insulation and Evaporative Resistance Values of Dutch Firefighter Clothing Items and Ensembles. BIOLOGY 2022; 11:biology11121813. [PMID: 36552322 PMCID: PMC9775573 DOI: 10.3390/biology11121813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022]
Abstract
The rescue operations' environment can impair firefighters' performance and increase the risk of injuries, e.g., burns and hyperthermia. The bulk and carried weight of heavy protection contributes to lower physical performance, higher metabolic load and internal body heat production. For recommending optimal protection for the tasks and incident scenarios, knowledge of clothing thermal properties is needed. However, detailed data on firefighter protective clothing systems are not available. The aim of the study was to provide scientific background and a dataset that would allow for validation of thermo-physiological models for task-specific conditions of rescue work. Thermal insulation of 37 single items and their variations and 25 realistic protective clothing ensembles were measured on a thermal manikin. Twelve (12) ensembles that evenly covered the whole insulation range were selected for evaporative resistance testing. The equations for summing up individual item's insulation to ensemble insulation and calculating clothing area factor were derived from the dataset. The database of a firefighter clothing system was created. In addition, the local and regional thermal properties of the clothing ensembles were provided for use in future validation of advanced thermo-physiological models for rescue worker exposure predictions and for designing decision aid tools.
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Affiliation(s)
- Kalev Kuklane
- Team Fire Service Science, Netherlands Academy of Crisis Management and Fire Service Science, Netherlands Institute for Public Safety, Zilverstraat 91, 2718 RP Zoetermeer, The Netherlands
| | - Jakob Eggeling
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Box 118, 22100 Lund, Sweden
| | - Maurice Kemmeren
- Team COLS, Netherlands Institute for Public Safety, Zilverstraat 91, 2718 RP Zoetermeer, The Netherlands
| | - Ronald Heus
- Team Fire Service Science, Netherlands Academy of Crisis Management and Fire Service Science, Netherlands Institute for Public Safety, Zilverstraat 91, 2718 RP Zoetermeer, The Netherlands
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13
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Yang J, Wang F, White MD, Li R, Song G, Etter CV, Gnatiuk EA, Perrotta AS. A 7-segment numerical hand-glove/mitten model for predicting thermophysiological responses of the human hand in extremely cold conditions. Comput Biol Med 2022; 151:106351. [PMID: 36459809 DOI: 10.1016/j.compbiomed.2022.106351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/03/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
A 7-segment and 29-node numerical hand-glove/mitten model was developed to simulate human hand physiological responses in various cold environments. To validate the model, simulated skin temperatures were compared to data from published literature and human trials conducted at -20, -40, and -60 °C. Results demonstrated that the model could reasonably predict cold-induced vasodilation (CIVD) responses at 0 °C temperature. At -20 °C, the model predicted skin temperature with the root mean square deviation (RMSD) falling within the measurement standard deviation (SD) for both the entire and local hand except for the posterior hand. At -40 and -60 °C, the model could predict the trend of the skin temperatures of the whole/local hand, but the RMSD was larger than the SD for the majority of predictions. A parametric analysis revealed that the palm and posterior hand had higher skin temperatures than the fingers, while the thumb had the lowest skin temperature of the fingers in all simulated cases except the case with a 3.5 clo mitten at -60 °C. The proposed numerical hand-glove/mitten model could reasonably predict local hand physiological responses in three extremely cold environments and provides fundamental knowledge for cold stress prediction and protective glove development, thereby improving the safety and health of industrial workers, firefighters, first responders, and troops.
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Affiliation(s)
- Jie Yang
- College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Faming Wang
- Division Animal and Human Health Engineering, Department of Biosystems (BIOSYST), KU Leuven, Kasteelpark Arenberg 30, BE-3001, Leuven, Belgium.
| | - Matthew David White
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Rui Li
- College of Human Sciences, Iowa State University, Ames, IA, 50010, USA
| | - Guowen Song
- College of Human Sciences, Iowa State University, Ames, IA, 50010, USA
| | - Clara V Etter
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Elizabeth A Gnatiuk
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Andrew S Perrotta
- Department of Kinesiology, University of Windsor, Ontario, N9B 3P4, Canada
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14
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Cramer MN, Gagnon D, Laitano O, Crandall CG. Human temperature regulation under heat stress in health, disease, and injury. Physiol Rev 2022; 102:1907-1989. [PMID: 35679471 PMCID: PMC9394784 DOI: 10.1152/physrev.00047.2021] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 05/10/2022] [Accepted: 05/28/2022] [Indexed: 12/30/2022] Open
Abstract
The human body constantly exchanges heat with the environment. Temperature regulation is a homeostatic feedback control system that ensures deep body temperature is maintained within narrow limits despite wide variations in environmental conditions and activity-related elevations in metabolic heat production. Extensive research has been performed to study the physiological regulation of deep body temperature. This review focuses on healthy and disordered human temperature regulation during heat stress. Central to this discussion is the notion that various morphological features, intrinsic factors, diseases, and injuries independently and interactively influence deep body temperature during exercise and/or exposure to hot ambient temperatures. The first sections review fundamental aspects of the human heat stress response, including the biophysical principles governing heat balance and the autonomic control of heat loss thermoeffectors. Next, we discuss the effects of different intrinsic factors (morphology, heat adaptation, biological sex, and age), diseases (neurological, cardiovascular, metabolic, and genetic), and injuries (spinal cord injury, deep burns, and heat stroke), with emphasis on the mechanisms by which these factors enhance or disturb the regulation of deep body temperature during heat stress. We conclude with key unanswered questions in this field of research.
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Affiliation(s)
- Matthew N Cramer
- Defence Research and Development Canada-Toronto Research Centre, Toronto, Ontario, Canada
| | - Daniel Gagnon
- Montreal Heart Institute and School of Kinesiology and Exercise Science, Université de Montréal, Montréal, Quebec, Canada
| | - Orlando Laitano
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
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15
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Wickham KA, Cheung SS. Finger anthropometrics may not be a primary influence on the thermal responses to cooling and rewarming. Temperature (Austin) 2022; 10:240-247. [PMID: 37332307 PMCID: PMC10274552 DOI: 10.1080/23328940.2022.2091901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 10/17/2022] Open
Abstract
The fingers have a large surface area to volume ratio (SA:V), minimal muscle mass, and potent vasoconstrictor capacity. These qualities make the fingers prone to heat loss and freezing injuries during whole-body or local cold exposure. Anthropologists have proposed that the large inter-individual variability in human finger anthropometrics may be an ecogeographic evolutionary adaptation, where shorter and thicker digits (i.e. smaller SA:V ratio) provide a favorable adaptation for cold climate natives. We hypothesized that the SA:V ratio of a digit has an inverse relationship with finger blood flux and finger temperature (Tfinger) during cooling and rewarming from cold. Fifteen healthy adults with no or limited cold experiment experience performed 10 min of baseline immersion in warm water (35.0 ± 0.1°C), 30 min in cold water (8.4 ± 0.2°C), and a final 10 min of rewarming in ambient air (~22°C, ~40% relative humidity). Tfinger and finger blood flux were measured continuously across multiple digits per participant. Average Tfinger (p = 0.05; R2 = 0.06) and area under the curve for Tfinger (p = 0.05; R2 = 0.07) during hand cooling showed significant, negative correlations to digit SA:V ratio. There was no relationship between digit SA:V ratio and blood flux (i.e. average blood flux and AUC) during cooling as well as between SA:V ratio and digit temperature (i.e. average Tfinger and AUC) or blood flux (i.e. average blood flux and AUC) during rewarming. Overall, digit anthropometrics do not appear to play a dominant role in extremity cold response.
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Affiliation(s)
- Kate A. Wickham
- Environmental Ergonomics Lab, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Stephen S. Cheung
- Environmental Ergonomics Lab, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
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16
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Haghayegh S, Khoshnevis S, Smolensky MH, Hermida RC, Castriotta RJ, Schernhammer E, Diller KR. Novel
temperature‐controlled
sleep system to improve sleep: a p
roof‐of‐concept
study. J Sleep Res 2022; 31:e13662. [DOI: 10.1111/jsr.13662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/14/2022] [Accepted: 05/13/2022] [Indexed: 01/08/2023]
Affiliation(s)
- Shahab Haghayegh
- Channing Division of Network Medicine Brigham and Women's Hospital and Harvard Medical School Boston Massachusetts USA
- Department of Biomedical Engineering Cockrell School of Engineering, The University of Texas at Austin Austin Texas USA
| | - Sepideh Khoshnevis
- Department of Biomedical Engineering Cockrell School of Engineering, The University of Texas at Austin Austin Texas USA
| | - Michael H. Smolensky
- Department of Biomedical Engineering Cockrell School of Engineering, The University of Texas at Austin Austin Texas USA
- Department of Internal Medicine, Division of Cardiology McGovern School of Medicine, The University of Texas Health Science Center at Houston Houston Texas USA
| | - Ramon C. Hermida
- Department of Biomedical Engineering Cockrell School of Engineering, The University of Texas at Austin Austin Texas USA
- Bioengineering and Chronobiology Laboratories Atlantic Research Center for Telecommunication Technologies, University of Vigo Vigo Spain
| | - Richard J. Castriotta
- Division of Pulmonary, Critical Care and Sleep Medicine Keck School of Medicine, University of Southern California Los Angeles California USA
| | - Eva Schernhammer
- Channing Division of Network Medicine Brigham and Women's Hospital and Harvard Medical School Boston Massachusetts USA
- Department of Epidemiology Center for Public Health, Medical University of Vienna Vienna Austria
- Department of Epidemiology Harvard TH Chan School of Public Health Boston Massachusetts USA
| | - Kenneth R. Diller
- Department of Biomedical Engineering Cockrell School of Engineering, The University of Texas at Austin Austin Texas USA
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17
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An Analytical Model to Predict Foot Sole Temperature: Implications to Insole Design for Physical Activity in Sport and Exercise. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12136806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Foot sole temperature, besides its importance in thermal comfort, can be considered an important factor in identifying tissue injuries due to heavy activities or diseases. Hyperthermia, which is a raise in the foot temperature, increases the risk of diabetic ulcers considerably. In this study, a model is proposed to predict the foot sole temperature with acceptable accuracy. This model for the first time considers both the thermal and mechanical properties of the shoe sole, the intensity of the activity, the ambient condition, and sweating, which are involved in the thermal interaction between the sole of the foot and footwear. Furthermore, the proposed model provides the opportunity to estimate the contributions of different parameters in foot thermal regulation by describing the interaction of activity, duration, and intensity as well as sweating in influencing the foot sole temperature. In doing so it takes into account the relative importance of heat capacitance and the thermal conductivity. The results of this study revealed that sweating is not as effective in cooling the ball area of the foot while it is the principal contributor to thermal regulation in the arch area. The model also showed the importance of trapped air in keeping the foot warm, especially in cold conditions. Based on the simulation results, in selecting the shoe sole, and in addition to the conductivity, the thermal capacity of the sole of the shoe needs to be considered. The developed analytical model allowed the investigation of the contribution of all the involved parameters in foot thermal regulation and has shown that a different foot temperature can be achieved when the amount of material versus air is changed in the insole design. This can have practical implications in the insole design for a variety of conditions such as hypo and hyper-thermia in physical activities in sports and exercise settings.
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18
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Van Duren A. Perioperative Prewarming: Heat Transfer and Physiology. AORN J 2022; 115:407-422. [PMID: 35476210 DOI: 10.1002/aorn.13667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/19/2021] [Accepted: 12/12/2021] [Indexed: 11/07/2022]
Abstract
To appreciate the strategy of prewarming, perioperative personnel should have a basic understanding of the physics of heat transfer and the thermoregulatory pathophysiology of anesthesia. The dominant cause of postinduction hypothermia is anesthesia-related redistribution of heat within the body; the role of cutaneous heat loss is minimal. Physiologic thermoregulatory system changes that occur in response to anesthesia make it almost impossible to reverse intraoperative hypothermia. However, prewarming is an effective strategy to prevent postinduction hypothermia from redistribution because it creates a temporary excess of heat in the body's peripheral thermal compartment. Perioperative nurses should implement active and passive prewarming strategies in accordance with the warming devices at their facility and available time. This article focuses on two major topics necessary to understand prewarming: the effect of anesthesia on postinduction thermoregulation and thermodynamic conditions that successful treatment strategies must exploit to produce desired outcomes.
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19
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Namisnak LH, Haghayegh S, Khoshnevis S, Diller KR. Bioheat Transfer Basis of Human Thermoregulation: Principles and Applications. JOURNAL OF HEAT TRANSFER 2022; 144:031203. [PMID: 35833149 PMCID: PMC8823203 DOI: 10.1115/1.4053195] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/06/2021] [Indexed: 05/29/2023]
Abstract
Thermoregulation is a process that is essential to the maintenance of life for all warm-blooded mammalian and avian species. It sustains a constant core body temperature in the face of a wide array of environmental thermal conditions and intensity of physical activities that generate internal heat. A primary component of thermoregulatory function is the movement of heat between the body core and the surface via the circulation of blood. The peripheral vasculature acts as a forced convection heat exchanger between blood and local peripheral tissues throughout the body enabling heat to be convected to the skin surface where is may be transferred to and from the environment via conduction, convection, radiation, and/or evaporation of water as local conditions dictate. Humans have evolved a particular vascular structure in glabrous (hairless) skin that is especially well suited for heat exchange. These vessels are called arteriovenous anastomoses (AVAs) and can vasodilate to large diameters and accommodate high flow rates. We report herein a new technology based on a physiological principle that enables simple and safe access to the thermoregulatory control system to allow manipulation of thermoregulatory function. The technology operates by applying a small amount of heating local to control tissue on the body surface overlying the cerebral spine that upregulates AVA perfusion. Under this action, heat exchangers can be applied to glabrous skin, preferably on the palms and soles, to alter the temperature of elevated blood flow prior to its return to the core. Therapeutic and prophylactic applications are discussed.
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Affiliation(s)
- Laura H Namisnak
- Department of Biomedical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX 78712
| | - Shahab Haghayegh
- Department of Biomedical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX 78712; Department of Biostatics, T.H. Chan School of Public Health, Harvard Medical School, Boston, MA 02138
| | - Sepideh Khoshnevis
- Department of Biomedical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX 78712
| | - Kenneth R Diller
- Department of Biomedical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX 78712
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20
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Fullagar H, Notley SR, Fransen J, Richardson A, Stadnyk A, Lu D, Brown G, Duffield R. Cooling strategies for firefighters: Effects on physiological, physical, and visuo-motor outcomes following fire-fighting tasks in the heat. J Therm Biol 2022; 106:103236. [DOI: 10.1016/j.jtherbio.2022.103236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/21/2022] [Accepted: 03/26/2022] [Indexed: 11/25/2022]
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21
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Vagedes J, Kuderer S, Helmert E, Vagedes K, Kohl M, Szőke H, Beissner F, Joos S, Andrasik F. The Immediate Effect of Sinapis nigra and Zingiber officinale as Thermogenic Substances during Footbaths: A Randomized Controlled Crossover Trial. Complement Med Res 2021; 29:213-222. [PMID: 34933309 PMCID: PMC9677831 DOI: 10.1159/000521590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/19/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Warm footbaths infused with Sinapis nigra (mustard, or MU) or Zingiber officinale (ginger, or GI) are used for various thermoregulatory conditions, but little is known about how they are perceived by individuals, both short- and long-term. We analyzed the immediate and long-term effects of MU and GI on warmth and stimulus perception in healthy adults. METHODS Seventeen individuals (mean age 22.1±2.4 years; 11 female) received three footbaths (mean temperature was 40 ± 0.2°C, administered between 1:30 and 6:30 p.m.) in a randomized order with a crossover design: 1. with warm water only (WA), 2. with warm water and MU, and 3. with warm water and GI. Warmth and stimulus perception at the feet were assessed at the 1st, 5th, 10th, 15th, and 20th minute of the footbaths, in the late evening (EVE), and the following morning (MG). We further assessed well-being (at EVE and MG) and sleep quality (at MG). The primary outcome measure was the warmth perception at the feet at the 10th minute of the footbath. RESULTS At the 10th minute of the footbath, warmth perception at the feet was significantly higher with MU and GI compared to WA. The immediate thermogenic effects pointed to a quick increase in warmth and stimulus perception with MU, a slower increase with GI, and a gradual decrease with WA. Regarding the long-term effects, warmth and stimulus perception were still higher after GI compared to WA at EVE and MG. No differences were seen for general well-being and sleep quality. CONCLUSION Thermogenic substances can significantly alter the dynamics of warmth and stimulus perception when added to footbaths. The different profiles in the application of GI and MU could be relevant for a more differentiated and specific use of both substances in different therapeutic indications.
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Affiliation(s)
- Jan Vagedes
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
- Department of Neonatology, University Hospital Tübingen, Tübingen, Germany
| | - Silja Kuderer
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - Eduard Helmert
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - Katrin Vagedes
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - Matthias Kohl
- Institute of Precision Medicine, University Furtwangen, Villingen-Schwenningen, Germany
| | - Henrik Szőke
- Department of Integrative Medicine, University of Pécs, Pécs, Hungary
| | - Florian Beissner
- Insula Institute for Integrative Therapy Research, Hannover, Germany
| | - Stefanie Joos
- Institute for General Practice and Interprofessional Care, University Hospital Tübingen, Tübingen, Germany
| | - Frank Andrasik
- Department of Psychology, University of Memphis, Memphis, Tennessee, USA
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22
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Favilla AB, Horning M, Costa DP. Advances in thermal physiology of diving marine mammals: The dual role of peripheral perfusion. Temperature (Austin) 2021; 9:46-66. [PMID: 35655662 PMCID: PMC9154795 DOI: 10.1080/23328940.2021.1988817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The ability to maintain a high core body temperature is a defining characteristic of all mammals, yet their diverse habitats present disparate thermal challenges that have led to specialized adaptations. Marine mammals inhabit a highly conductive environment. Their thermoregulatory capabilities far exceed our own despite having limited avenues of heat transfer. Additionally, marine mammals must balance their thermoregulatory demands with those associated with diving (i.e. oxygen conservation), both of which rely on cardiovascular adjustments. This review presents the progress and novel efforts in investigating marine mammal thermoregulation, with a particular focus on the role of peripheral perfusion. Early studies in marine mammal thermal physiology were primarily performed in the laboratory and provided foundational knowledge through in vivo experiments and ex vivo measurements. However, the ecological relevance of these findings remains unknown because comparable efforts on free-ranging animals have been limited. We demonstrate the utility of biologgers for studying their thermal adaptations in the context in which they evolved. Our preliminary results from freely diving northern elephant seals (Mirounga angustirostris) reveal blubber’s dynamic nature and the complex interaction between thermoregulation and the dive response due to the dual role of peripheral perfusion. Further exploring the potential use of biologgers for measuring physiological variables relevant to thermal physiology in other marine mammal species will enhance our understanding of the relative importance of morphology, physiology, and behavior for thermoregulation and overall homeostasis.
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Affiliation(s)
- Arina B. Favilla
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States
| | - Markus Horning
- Wildlife Technology Frontiers, Seward, AK, United States
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States
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23
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Sullivan-Kwantes W, Haman F, Kingma BRM, Martini S, Gautier-Wong E, Chen KY, Friedl KE. Human performance research for military operations in extreme cold environments. J Sci Med Sport 2021; 24:954-962. [PMID: 33358087 DOI: 10.1016/j.jsams.2020.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/06/2020] [Accepted: 11/17/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Soldier performance in the Arctic depends on planning and training, protective equipment, and human physiological limits. The purpose of this review was to highlight the span of current research on enhancing soldier effectiveness in extreme cold and austere environments. METHODS The practices of seasoned soldiers who train in the Arctic and cold-dwelling natives inform performance strategies. We provide examples of research and technology that build on these concepts. RESULTS Examples of current performance research include evaluation of equipment and tactics such as the bioenergetics of load carriage over snow in Norwegian exercises; Canadian field monitoring of hand temperatures and freezing cold injuries for better protection of manual dexterity; and Dutch predictive modeling of cold-wet work tolerances. Healthy young men can respond to cold with a substantial thermogenic response based on US and Canadian studies on brown adipose tissue and other mechanisms of non-shivering thermogenesis; the potential advantage of greater fat insulation is offset in obese unfit subjects by a smaller thermogenic response. Current physiological studies are addressing previously unanswered problems of cold acclimation procedures, thermogenic enhancement and regulation, and modulation of sympathetic activation, all of which may further enhance cold survival and expand the performance envelope. CONCLUSION There is an inseparable behavioral component to soldier performance in the Arctic, and even the best equipment does not benefit soldiers who have not trained in the actual environment. Training inexperienced soldiers to performance limits may be helped with personal monitoring technologies and predictive models.
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Affiliation(s)
| | | | - Boris R M Kingma
- TNO, The Netherlands Organization for Applied Sciences, Soesterberg, The Netherlands
| | - Svein Martini
- Norwegian Defence Research Establishment, Kjeller, Norway
| | - Emilie Gautier-Wong
- Les Voltigeurs de Québec, 35 Canadian Brigade Group, Quebec City, Quebec, Canada
| | - Kong Y Chen
- NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | - Karl E Friedl
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
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24
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Smith LL. The Central Role of Hypothermia and Hyperactivity in Anorexia Nervosa: A Hypothesis. Front Behav Neurosci 2021; 15:700645. [PMID: 34421554 PMCID: PMC8377352 DOI: 10.3389/fnbeh.2021.700645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/24/2021] [Indexed: 12/24/2022] Open
Abstract
Typically, the development of anorexia nervosa (AN) is attributed to psycho-social causes. Several researchers have recently challenged this view and suggested that hypothermia and hyperactivity (HyAc) are central to AN. The following hypothesis will attempt to clarify their role in AN. Anorexia nervosa patients (ANs) have significantly lower core temperatures (Tcore) compared to healthy controls (HCs). This reduced temperature represents a reset Tcore that needs to be maintained. However, ANs cannot maintain this Tcore due primarily to a reduced basal metabolic rate (BMR); BMR usually supplies heat to sustain Tcore. Therefore, to generate the requisite heat, ANs revert to the behavioral-thermoregulatory strategy of HyAc. The majority of ANs (~89%) are reportedly HyAc. Surprisingly, engagement in HyAc is not motivated by a conscious awareness of low Tcore, but rather by the innocuous sensation of "cold- hands" frequently reported by ANs. That is, local hand-thermoreceptors signal the brain to initiate HyAc, which boosts perfusion of the hands and alters the sensation of "cold-discomfort" to one of "comfort." This "rewarding" consequence encourages repetition/habit formation. Simultaneously, hyperactivity increases the availability of heat to assist with the preservation of Tcore. Additionally, HyAc induces the synthesis of specific brain neuromodulators that suppress food intake and further promote HyAc; this outcome helps preserve low weight and perpetuates this vicious cycle. Based on this hypothesis and supported by rodent research, external heat availability should reduce the compulsion to be HyAc to thermoregulate. A reduction in HyAc should decrease the production of brain neuromodulators that suppress appetite. If verified, hopefully, this hypothesis will assist with the development of novel treatments to aid in the resolution of this intractable condition.
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Affiliation(s)
- Lucille Lakier Smith
- Human Performance Laboratory, Department of Kinesiology, School of Health Sciences, East Carolina University, Greenville, NC, United States
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25
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Jimenez-Perez I, Gil-Calvo M, Salvador-Palmer R, Cibrián Ortiz de Anda RM, Pérez-Soriano P, Priego-Quesada JI. Footwear outsole temperature may be more related to plantar pressure during a prolonged run than foot temperature. Physiol Meas 2021; 42. [PMID: 34186519 DOI: 10.1088/1361-6579/ac0fbe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/29/2021] [Indexed: 11/12/2022]
Abstract
Objective. The temperature of the sole of the foot has been suggested as an alternative to the measurement of plantar pressure during running despite the scarce evidence about their relationship. The temperature of the footwear outsole could also be representative of plantar pressure distribution due to its less multifactorial dependence. The aim of the study was to determine if plantar pressure during a prolonged run could be related to plantar temperature, either of the sole of the foot or the footwear outsole.Approach. Thirty recreational runners (15 males and 15 females) performed a 30 min running test on a treadmill. Thermographic images of the sole of the foot and the footwear outsole were taken before and immediately after the test, and dynamic plantar pressure was measured at the end of the test. Pearson correlations and stepwise multiple linear regressions were performed.Main results.Plantar pressure percentage was related to a moderate correlation with plantar temperature percentage in forefoot and rearfoot (P < 0.05), showing a greater relationship with the footwear outsole than with the sole of the foot (r = 0.52-0.73 versusr = 0.40-0.61, respectively). Moreover, moderate correlations were also observed between footwear outsole and sole of the foot temperature variables, especially in rearfoot.Significance. Footwear outsole temperature may be better related to plantar pressure distribution than sole of the foot temperature, in the forefoot and rearfoot. The midfoot is the most sensitive and variable region to analyze, as it does not seem to have any relationship with plantar pressure.
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Affiliation(s)
- Irene Jimenez-Perez
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, St: Gascó Oliag, 3, E-46010, Valencia, Spain.,Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, Ave: Blasco Ibáñez, 15, E-46010, Valencia, Spain
| | - Marina Gil-Calvo
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, St: Gascó Oliag, 3, E-46010, Valencia, Spain.,Department of Physiatry and Nursing, Faculty of Health and Sport Science (FCSD), University of Zaragoza, Ronda Misericordia, 5, E-22001 Huesca, Spain
| | - Rosario Salvador-Palmer
- Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, Ave: Blasco Ibáñez, 15, E-46010, Valencia, Spain
| | - Rosa Ma Cibrián Ortiz de Anda
- Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, Ave: Blasco Ibáñez, 15, E-46010, Valencia, Spain
| | - Pedro Pérez-Soriano
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, St: Gascó Oliag, 3, E-46010, Valencia, Spain
| | - Jose Ignacio Priego-Quesada
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, St: Gascó Oliag, 3, E-46010, Valencia, Spain.,Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, Ave: Blasco Ibáñez, 15, E-46010, Valencia, Spain
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26
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Finger constrictor and thermoperceptual responsiveness to localised cooling following 5 weeks of intermittent regional exposures to moderately augmented transmural vascular pressure. Microvasc Res 2021; 137:104181. [PMID: 34015276 DOI: 10.1016/j.mvr.2021.104181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/15/2021] [Accepted: 05/13/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE To examine the effects of prolonged intermittent exposures to moderately increased transmural pressure on finger vasoreactivity and thermoperception to localised cooling. METHODS Eleven men completed a 5-week regimen (3 sessions·week-1; 55 min·session-1), during which the vasculature in one arm (EXP) was exposed intermittently (10-min exposure: 5-min pause) to increased transmural pressure (from +65 mmHg week-1 to +105 mmHg week-5). Before and after the regimen, finger cutaneous vascular conductance (CVC), temperature (Tavg), and thermoperception (thermal sensation, discomfort and pain) were monitored during a 30-min hand cold (8 °C water) provocation trial. The responses of the non-trained hand were examined during an additional cold trial. RESULTS After the regimen, baseline finger CVC and Tavg were higher in both hands (p ≤ 0.01). During cooling, neither finger CVC nor Tavg were modified (p > 0.05). Yet the magnitude of the cold-induced drop of CVC was augmented in both hands, and to a similar extent (p ≤ 0.02). The regimen alleviated thermal pain in both hands (p ≤ 0.02); the sensation of coldness and thermal discomfort were attenuated mainly in the EXP hand (p = 0.02). CONCLUSIONS Present findings indicate that iterative local exposures to augmented intravascular pressure do not alter finger vasoreactivity to localised cooling. The pressure training, however, might impair finger basal vasomotor tone, and aggravate the magnitude of constrictor responsiveness to cooling. The pressure training also elicits thermoperceptual desensitisation to noxious thermal stimulus. To large extent, these vascular and perceptual adjustments seem to be transferred to the cutaneous vasculature of the non-trained limb.
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Taylor NAS, Lee JY, Kim S, Notley SR. Physiological interactions with personal-protective clothing, physically demanding work and global warming: An Asia-Pacific perspective. J Therm Biol 2021; 97:102858. [PMID: 33863427 DOI: 10.1016/j.jtherbio.2021.102858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 01/03/2023]
Abstract
The Asia-Pacific contains over half of the world's population, 21 countries have a Gross Domestic Product <25% of the world's largest economy, many countries have tropical climates and all suffer the impact of global warming. That 'perfect storm' exacerbates the risk of occupational heat illness, yet first responders must perform physically demanding work wearing personal-protective clothing and equipment. Unfortunately, the Eurocentric emphasis of past research has sometimes reduced its applicability to other ethnic groups. To redress that imbalance, relevant contemporary research has been reviewed, to which has been added information applicable to people of Asian, Melanesian and Polynesian ancestry. An epidemiological triad is used to identify the causal agents and host factors of work intolerance within hot-humid climates, commencing with the size dependency of resting metabolism and heat production accompanying load carriage, followed by a progression from the impact of single-layered clothing through to encapsulating ensembles. A morphological hypothesis is presented to account for inter-individual differences in heat production and heat loss, which seems to explain apparent ethnic- and gender-related differences in thermoregulation, at least within thermally compensable states. The mechanisms underlying work intolerance, cardiovascular insufficiency and heat illness are reviewed, along with epidemiological data from the Asia-Pacific. Finally, evidence-based preventative and treatment strategies are presented and updated concerning moisture-management fabrics and barriers, dehydration, pre- and post-exercise cooling, and heat adaptation. An extensive reference list is provided, with >25 recommendations enabling physiologists, occupational health specialists, policy makers, purchasing officers and manufacturers to rapidly extract interpretative outcomes pertinent to the Asia-Pacific.
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Affiliation(s)
- Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
| | - Joo-Young Lee
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea
| | - Siyeon Kim
- Human Convergence Technology R&D Department, Korea Institute of Industrial Technology, Ansan, Republic of Korea
| | - Sean R Notley
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
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Vagedes J, Kuderer S, Vagedes K, Hiller S, Beissner F, Szőke H, Joos S, Wolf U. Increasing Warmth in Oncological Patients: A Randomized Controlled Cross-Over Pilot Trial Examining the Efficacy of Mustard and Ginger Footbaths. Integr Cancer Ther 2021; 20:15347354211058449. [PMID: 34814768 PMCID: PMC8647243 DOI: 10.1177/15347354211058449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/09/2021] [Accepted: 10/21/2021] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE To analyze the thermogenic effects of footbaths with medicinal powders in oncological patients (ON) and healthy controls (HC). INTERVENTION AND OUTCOMES Thirty-six participants (23 ON, 13 HC; 24 females; 49.9 ± 13.3 years) received 3 footbaths in a random order with cross-over design: warm water only (WA), warm water plus mustard (MU, Sinapis nigra), and warm water plus ginger (GI, Zingiber officinale). Warmth perception of the feet (Herdecke Warmth Perception Questionnaire, HeWEF) at the follow-up (10 minutes after completion of footbaths, t2) was assessed as the primary outcome measure. Secondary outcome measures included overall warmth as well as self-reported warmth (HeWEF) and measured skin temperature (high resolution thermography) of the face, hands and feet at baseline (t0), post immersion (t1), and follow-up (t2). RESULTS With respect to the warmth perception of the feet, GI and MU differed significantly from WA (P's < .05) with the highest effect sizes at t1 (WA vs GI, d = 0.92, WA vs MU, d = 0.73). At t2, perceived warmth tended to be higher with GI compared to WA (d = 0.46). No differences were detected between ON and HC for self-reported warmth. With respect to skin temperatures, face and feet skin temperatures of ON were colder (at t0 and t1, 0.42 ≥ d ≥ 0.68) and tended to have diametrical response patterns than HC (ON vs HC: colder vs warmer after MU). CONCLUSION Among adult oncological patients and healthy controls, footbaths with mustard and ginger increased warmth perception of the feet longer than with warm water only. The potential impact of regularly administered thermogenic footbaths over extended periods merits further investigation for the recovery of cancer-related sense of cold.
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Affiliation(s)
- Jan Vagedes
- ARCIM Institute, Filderstadt,
Germany
- University Hospital Tuebingen,
Tuebingen, Germany
- Filderklinik, Filderstadt,
Germany
| | | | | | | | - Florian Beissner
- Insula Institute for Integrative
Therapy Research, Hannover, Germany
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Valenza A, Charlier H, Bianco A, Filingeri D. Independent and interactive effects of thermal stress and mental fatigue on manual dexterity. Am J Physiol Regul Integr Comp Physiol 2020; 319:R703-R711. [PMID: 33074012 DOI: 10.1152/ajpregu.00226.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many occupations and sports require high levels of manual dexterity under thermal stress and mental fatigue. Yet, multistressor studies remain scarce. We quantified the interactive effects of thermal stress and mental fatigue on manual dexterity. Seven males (21.1 ± 1.3 yr) underwent six separate 60-min trials characterized by a combination of three air temperatures (hot, 37°C; neutral, 21°C; cold, 7°C) and two mental fatigue states (MF, mental fatigue induced by a 35-min cognitive battery; no-MF, no mental fatigue). Participants performed complex (O'Connor test) and simple (hand-tool test) manual tasks pre- and posttrial to determine stressor-induced performance changes. We monitored participants' rectal temperature and hand skin temperature (Thand) continuously and assessed the reaction time (hand-click test) and subjective mental fatigue (5-point scale). Thermal stress (P < 0.0001), but not mental fatigue (P = 0.290), modulated Thand (heat, +3.3°C [95% CI: +0.2, +6.5]; cold, -7.5°C [-10.7, -4.4]). Mental fatigue (P = 0.021), but not thermal stress (P = 0.646), slowed the reaction time (∼10%) and increased subjective fatigue. Thermal stress and mental fatigue had an interactive effect on the complex manual task (P = 0.040), with cold-no-MF decreasing the performance by -22% [-39, -5], whereas neutral-MF, cold-MF, and heat-MF by -36% [-53, -19], -34% [-52, -17], and -36% [-53, -19], respectively. Only mental fatigue decreased the performance in the simple manual task (-30% [-43, -16] across all thermal conditions; P = 0.002). Cold stress-induced impairments in complex manipulation increase with mental fatigue; yet combined stressors' effects are no greater than those of mental fatigue alone, which also impairs simple manipulation. Mental fatigue poses a greater challenge to manual dexterity than thermal stress.
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Affiliation(s)
- Alessandro Valenza
- THERMOSENSELAB, Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom.,Sport and Exercise Sciences Research Unit, Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy
| | - Harry Charlier
- THERMOSENSELAB, Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Antonino Bianco
- Sport and Exercise Sciences Research Unit, Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy
| | - Davide Filingeri
- THERMOSENSELAB, Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
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30
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Nemati H, Moghimi MA, Naemi R. A mathematical model to investigate heat transfer in footwear during walking and jogging. J Therm Biol 2020; 97:102778. [PMID: 33863456 DOI: 10.1016/j.jtherbio.2020.102778] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 11/30/2022]
Abstract
Foot temperature during activities of daily living affects the human performance and well-being. Footwear thermal characteristics affect the foot temperature inside the shoe during activities of daily living. The temperate at the sole of the foot (plantar temperature) is influenced by different thermal properties such as heat capacity, heat diffusivity, and thermal conductivity of the shoe sole in addition to its mechanical properties. Hence the purpose of this study was to propose a method to allow investigating the effect of footwear thermal characteristics on the foot temperature during activities of daily living, like walking or jogging. The transient heat transfer between the foot and the ground was studied to drive the governing equation for heat transfer modelling in footwear and to predict foot sole temperature during walking, and jogging. Different thermo-mechanical properties of shoe sole, as well as geometrical parameters, were investigated. The proposed model showed to be able to adequately predict the plantar temperature at the ball of the foot when compared to the results from experimental measurements. Finally, using the proposed method, the thermal behaviour of two different shoes with two different sole materials EVA08 and EVA12 were compared. It was shown that heat capacity as compared to the thermal conductivity of the shoe sole is more effective in reducing the plantar temperature increase in short term. The proposed method proved to be able to accurately predict the thermal behaviour of shoes and can provide a tool to predict footwear thermal comfort.
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Affiliation(s)
- H Nemati
- Department of Mechanics, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran.
| | - M A Moghimi
- Department of Design and Engineering, Staffordshire University, Stoke-On-Trent ST4 2DE, UK
| | - Roozbeh Naemi
- Centre for Biomechanics and Rehabilitation Technologies, Staffordshire University, Leek Road, Stoke on Trent ST4 2DF, UK
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Westcott S, Wung W, Schelegle A, Ganaga S, Schaefer S. "Cool Knees" as a Measure of Systemic Vascular Resistance in Cardiac Patients. Cureus 2020; 12:e11304. [PMID: 33282581 PMCID: PMC7714722 DOI: 10.7759/cureus.11304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction: Clinical assessment of cardiac output (CO) and systemic vascular resistance (SVR) in cardiac patients is often inaccurate. Since the genicular arteries form a watershed zone accessible to physical examination, we hypothesized that “cool knees” would reflect abnormalities in central hemodynamics. Methods: Nineteen patients with cardiac diagnoses, but without distributive shock, had a measurement of skin temperature over the thigh, knee, and foot in parallel with central hemodynamics derived from invasive monitoring. Results: The temperature gradient from thigh to knee (DTK) reflected increased SVR, and was significantly correlated with SVR, cardiac index (CI), and CO. Cool feet (DTF) were significantly correlated only with systemic hypotension, but not central hemodynamics. Conclusion: Cool knees reflect increased SVR in cardiac patients and may be an important physical exam finding in their assessment and management.
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Affiliation(s)
- Sarah Westcott
- Internal Medicine, University of California Davis Health System, Sacramento, USA
| | - William Wung
- Internal Medicine, University of California Davis Health System, Sacramento, USA
| | - Aaron Schelegle
- Internal Medicine, University of California Davis Health System, Sacramento, USA
| | - Svetlana Ganaga
- Cardiothoracic Surgery, University of California Davis Health System, Sacramento, USA
| | - Saul Schaefer
- Internal Medicine, University of California Davis Health System, Sacramento, USA
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32
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Carceller A, González Torcal JP, Viscor G. Topical Nifedipine Administration for Secondary Prevention in Frostbitten Patients. Front Physiol 2020; 11:695. [PMID: 32655415 PMCID: PMC7326014 DOI: 10.3389/fphys.2020.00695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/27/2020] [Indexed: 11/13/2022] Open
Abstract
Frostbite is a cold-related injury with a growing incidence among healthy subjects. Sequelae after frostbite are frequent and vary among individuals. Here, we studied the thermal response in the digits of hands and feet of five subjects who had recovered from previous frostbite, except for their lasting sequelae. We considered three different conditions: digits unaffected by frostbite nor sequelae (healthy), those affected but which did not suffer amputation (frostbitten without amputation), and the remainder/stumps of digits that underwent partial amputation (frostbitten with amputation). Three consecutive immersions in cold water (8°C; 3 min) interspersed by 1 minute of thermal recovery were performed. After 30 min, a topical 10% nifedipine preparation was applied to hands and feet, and the same cold exposure protocol to evaluate its effect was followed. In basal condition and immediately after each immersion, the temperature of individual digits was assessed using thermography. We observed different thermal responses among the different digits of hands and feet, even without the nifedipine treatment. Nifedipine had a cooling effect on healthy and post-amputated tissue without thermal stress. In cold conditions, topic nifedipine application improved the cold response in healthy fingers but had a negative effect on those from which parts had been amputated. The topical nifedipine had detrimental effects on toes in all conditions. Topical nifedipine can help to the preservation of healthy fingers exposed to cold, with adequate thermal insulation; but it is necessary to remark its potentially harmful effects on previously frostbitten tissue. Because of the differences observed on individual regional response to cold, thermography can be a useful tool in the frostbite prevention for subjects habitually exposed to cold environment.
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Affiliation(s)
- Anna Carceller
- Secció de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Juan Pedro González Torcal
- Secció de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Ginés Viscor
- Secció de Fisiologia, Departament de Biologia Cel⋅lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Douzi W, Dupuy O, Theurot D, Smolander J, Dugué B. Per-Cooling (Using Cooling Systems during Physical Exercise) Enhances Physical and Cognitive Performances in Hot Environments. A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1031. [PMID: 32041228 PMCID: PMC7036802 DOI: 10.3390/ijerph17031031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/25/2020] [Accepted: 01/29/2020] [Indexed: 12/19/2022]
Abstract
There are many important sport events that are organized in environments with a very hot ambient temperature (Summer Olympics, FIFA World Cup, Tour de France, etc.) and in hot locations (e.g., Qatar). Additionally, in the context of global warming and heat wave periods, athletes are often subjected to hot ambient temperatures. It is known that exercising in the heat induces disturbances that may provoke premature fatigue and negatively affects overall performance in both endurance and high intensity exercises. Deterioration in several cognitive functions may also occur, and individuals may be at risk for heat illnesses. To train, perform, work and recover and in a safe and effective way, cooling strategies have been proposed and have been routinely applied before, during and after exercise. However, there is a limited understanding of the influences of per-cooling on performance, and it is the subject of the present review. This work examines the influences of per-cooling of different areas of the body on performance in terms of intense short-term exercises ("anaerobic" exercises), endurance exercises ("aerobic" exercises), and cognitive functioning and provides detailed strategies that can be applied when individuals train and/or perform in high ambient temperatures.
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Affiliation(s)
| | | | | | | | - Benoit Dugué
- University of Poitiers, Laboratoire Mobilité Vieillissement Exercice (MOVE)-EA6314, Faculty of Sport Sciences, 8 Allée Jean Monnet, 86000 Poitiers, France; (W.D.); (O.D.); (D.T.); (J.S.)
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TOKIZAWA K, SON SY, OKA T, YASUDA A. Effectiveness of a field-type liquid cooling vest for reducing heat strain while wearing protective clothing. INDUSTRIAL HEALTH 2020; 58:63-71. [PMID: 31406053 PMCID: PMC6997718 DOI: 10.2486/indhealth.2018-0182] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 06/25/2019] [Indexed: 05/27/2023]
Abstract
This study examined the effectiveness of a field-type liquid cooling vest (LCV) worn underneath an impermeable protective suit on heat strain during walking. Eight men walked for 60 min at a moderate speed (3.0 km/h) wearing the suit in a warm environment (33°C, 60% relative humidity) without (control, CON) or with the LCV. A smaller increase in rectal temperature was recorded in participants in the LCV than in the CON condition (37.6 ± 0.1°C vs. 37.9 ± 0.1°C, p<0.05). Walking while wearing the LCV reduced the level of physiological heat strain, as measured by the mean skin temperature (35.5 ± 0.1°C vs. 36.3 ± 0.1°C), chest sweat rate (13.5 ± 3.0 mg/cm2/h vs. 16.6 ± 3.8 mg/cm2/h), chest cutaneous vascular conductance (349 ± 88% vs. 463 ± 122%), body weight loss (0.72 ± 0.05% vs. 0.93 ± 0.06%), and heart rate (101 ± 6 beats/min vs. 111 ± 7 beats/min) (p<0.05, for all comparisons). These changes were accompanied by a decrease in thermal sensation and discomfort. These results suggest that a field-type LCV attenuates exertional heat strain while wearing impermeable protective clothing.
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Affiliation(s)
- Ken TOKIZAWA
- National Institute of Occupational Safety and Health,
Japan
| | - Su-Young SON
- National Institute of Occupational Safety and Health,
Japan
- Present address: Kyungpook National University, Korea
| | - Tatsuo OKA
- National Institute of Occupational Safety and Health,
Japan
| | - Akinori YASUDA
- National Institute of Occupational Safety and Health,
Japan
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35
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Increasing Warmth in Adolescents with Anorexia Nervosa: A Randomized Controlled Crossover Trial Examining the Efficacy of Mustard and Ginger Footbaths. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:2416582. [PMID: 32076439 PMCID: PMC7013347 DOI: 10.1155/2020/2416582] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/11/2019] [Accepted: 01/07/2020] [Indexed: 01/05/2023]
Abstract
Objective To analyze the thermogenic effects of footbaths with medicinal powders in adolescents with anorexia nervosa (AN) in comparison to healthy controls (HCs). Intervention and Outcomes. Forty-one female participants (21 AN, 20 HCs; 14.22 ± 1.54 years) received three footbaths-warm water and mustard (MU, Sinapis nigra), warm water and ginger (GI, Zingiber officinale), or warm water only (WA), in random order within a crossover design. Data were collected before (t1), immediately after foot immersion (maximum 20 minutes) (t2), and after 10 minutes subsequently (t3). Actual skin temperature (high resolution thermography) and perceived warmth (HeWEF questionnaire) were assessed at each time point for various body parts. The primary outcome measure was self-perceived warmth at the feet at t3. Secondary outcome measures were objective skin temperature and subjective warmth at the face, hands, and feet. Results Perceived warmth at the feet at t3 was significantly higher after GI compared to WA (mean difference -1.02) and MU (-1.07), with no differences between those with AN and HC (-0.29). For the secondary outcome measures, a craniocaudal temperature gradient for the skin temperature (thermography) was noted at t1 for patients with AN and HC (AN with colder feet). The craniocaudal gradient for subjective warmth was only seen for patients with AN. Conclusion Footbaths with ginger increased warmth perception at the feet longer than with mustard or warm water only for adolescents with AN as well as for HC. The impact of ginger footbaths on recovery of thermoregulatory disturbances in patients with AN repeated over extended periods merits further investigation.
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36
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Low DA, Jones H, Cable NT, Alexander LM, Kenney WL. Historical reviews of the assessment of human cardiovascular function: interrogation and understanding of the control of skin blood flow. Eur J Appl Physiol 2019; 120:1-16. [PMID: 31776694 PMCID: PMC6969866 DOI: 10.1007/s00421-019-04246-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/19/2019] [Indexed: 02/06/2023]
Abstract
Several techniques exist for the determination of skin blood flow that have historically been used in the investigation of thermoregulatory control of skin blood flow, and more recently, in clinical assessments or as an index of global vascular function. Skin blood flow measurement techniques differ in their methodology and their strengths and limitations. To examine the historical development of techniques for assessing skin blood flow by describing the origin, basic principles, and important aspects of each procedure and to provide recommendations for best practise. Venous occlusion plethysmography was one of the earliest techniques to intermittently index a limb’s skin blood flow under conditions in which local muscle blood flow does not change. The introduction of laser Doppler flowmetry provided a method that continuously records an index of skin blood flow (red cell flux) (albeit from a relatively small skin area) that requires normalisation due to high site-to-site variability. The subsequent development of laser Doppler and laser speckle imaging techniques allows the mapping of skin blood flow from larger surface areas and the visualisation of capillary filling from the dermal plexus in two dimensions. The use of iontophoresis or intradermal microdialysis in conjunction with laser Doppler methods allows for the local delivery of pharmacological agents to interrogate the local and neural control of skin blood flow. The recent development of optical coherence tomography promises further advances in assessment of the skin circulation via three-dimensional imaging of the skin microvasculature for quantification of vessel diameter and vessel recruitment.
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Affiliation(s)
- David A Low
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK.
| | - Helen Jones
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - N Tim Cable
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Liverpool, UK
| | - Lacy M Alexander
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - W Larry Kenney
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
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The origin, significance and plasticity of the thermoeffector thresholds: Extrapolation between humans and laboratory rodents. J Therm Biol 2019; 85:102397. [DOI: 10.1016/j.jtherbio.2019.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/05/2019] [Accepted: 08/05/2019] [Indexed: 01/07/2023]
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Bischof JC, Diller KR. From Nanowarming to Thermoregulation: New Multiscale Applications of Bioheat Transfer. Annu Rev Biomed Eng 2019; 20:301-327. [PMID: 29865870 DOI: 10.1146/annurev-bioeng-071516-044532] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This review explores bioheat transfer applications at multiple scales from nanoparticle (NP) heating to whole-body thermoregulation. For instance, iron oxide nanoparticles are being used for nanowarming, which uniformly and quickly rewarms 50-80-mL (≤5-cm-diameter) vitrified systems by coupling with radio-frequency (RF) fields where standard convective warming fails. A modification of this approach can also be used to successfully rewarm cryopreserved fish embryos (∼0.8 mm diameter) by heating previously injected gold nanoparticles with millisecond pulsed laser irradiation where standard convective warming fails. Finally, laser-induced heating of gold nanoparticles can improve the sensitivity of lateral flow assays (LFAs) so that they are competitive with laboratory tests such as the enzyme-linked immunosorbent assay. This approach addresses the main weakness of LFAs, which are otherwise the cheapest, easiest, and fastest to use point-of-care diagnostic tests in the world. Body core temperature manipulation has now become possible through selective thermal stimulation (STS) approaches. For instance, simple and safe heating of selected areas of the skin surface can open arteriovenous anastomosis flow in glabrous skin when it is not already established, thereby creating a convenient and effective pathway to induce heat flow between the body core and environment. This has led to new applications of STS to increase or decrease core temperatures in humans and animals to assist in surgery (perioperative warming), to aid ischemic stress recovery (cooling), and even to enhance the quality of sleep. Together, these multiscale applications of nanoparticle heating and thermoregulation point to dramatic opportunities for translation and impact in these prophylactic, preservative, diagnostic, and therapeutic applications of bioheat transfer.
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Affiliation(s)
- John C Bischof
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA;
| | - Kenneth R Diller
- Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
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Taylor NA, Nykvist Å, Powers N, Caldwell JN. Thermoeffector threshold plasticity: The impact of thermal pre-conditioning on sudomotor, cutaneous vasomotor and thermogenic thresholds. J Therm Biol 2019; 83:37-46. [DOI: 10.1016/j.jtherbio.2019.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022]
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Kim S, Kim DH, Lee HH, Lee JY. Frequency of firefighters' heat-related illness and its association with removing personal protective equipment and working hours. INDUSTRIAL HEALTH 2019; 57:370-380. [PMID: 30210098 PMCID: PMC6546580 DOI: 10.2486/indhealth.2018-0063] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 09/03/2018] [Indexed: 06/04/2023]
Abstract
The purpose of this study was to examine the frequency of firefighters' heat-related illness (HRI) in the line of duty with relation to resting/working hours and the behaviour of taking off PPE during rest periods based on nationwide survey (N=674). The results showed that 74.8% of firefighters experienced HRI symptoms and 5% of firefighters suffered from symptoms of HRI 20 times or more in a year. This study also showed a statistically significant correlation between working hours and removing PPE with the experience of HRI symptoms (p<0.05). In addition, removing PPE except the helmet was correlated with resting hours (p<0.001; Gloves: p=0.051), which indicates that removing PPE is related to resting time. This study revealed that firefighters routinely experienced mild HRI symptoms and the fatalities were just a tiny fraction. It is also emphasized that attention should be given on the significant role of taking off PPE during rest and on the standardized firefighters' rehabilitation followed by its application.
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Affiliation(s)
- Siyeon Kim
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Republic of Korea
- Human Convergence Technology R&D Group, Korea Institute of Industrial Technology, Republic of Korea
| | - Do-Hee Kim
- Research Institute of Human Ecology, Seoul National University, Republic of Korea
| | - Hyo-Hyun Lee
- Research Institute of Human Ecology, Seoul National University, Republic of Korea
| | - Joo-Young Lee
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Republic of Korea
- Research Institute of Human Ecology, Seoul National University, Republic of Korea
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Loughran SP, Verrender A, Dalecki A, Burdon CA, Tagami K, Park J, Taylor NAS, Croft RJ. Radiofrequency Electromagnetic Field Exposure and the Resting EEG: Exploring the Thermal Mechanism Hypothesis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16091505. [PMID: 31035391 PMCID: PMC6539668 DOI: 10.3390/ijerph16091505] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/08/2019] [Accepted: 04/25/2019] [Indexed: 01/15/2023]
Abstract
There is now strong evidence that radiofrequency electromagnetic field (RF-EMF) exposure influences the human electroencephalogram (EEG). While effects on the alpha band of the resting EEG have been repeatedly shown, the mechanisms underlying that effect have not been established. The current study used well-controlled methods to assess the RF-EMF exposure effect on the EEG and determine whether that effect might be thermally mediated. Thirty-six healthy adults participated in a randomized, double-blind, counterbalanced provocation study. A water-perfusion suit (34 °C) was worn throughout the study to negate environmental influences and stabilize skin temperature. Participants attended the laboratory on four occasions, the first being a calibration session and the three subsequent ones being exposure sessions. During each exposure session, EEG and skin temperature (8 sites) were recorded continuously during a baseline phase, and then during a 30 min exposure to a 920 MHz GSM-like signal (Sham, Low RF-EMF (1 W/kg) and High RF-EMF (2 W/kg)). Consistent with previous research, alpha EEG activity increased during the High exposure condition compared to the Sham condition. As a measure of thermoregulatory activation, finger temperature was found to be higher during both exposure conditions compared to the Sham condition, indicating for the first time that the effect on the EEG is accompanied by thermoregulatory changes and suggesting that the effect of RF-EMF on the EEG is consistent with a thermal mechanism.
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Affiliation(s)
- Sarah P Loughran
- Australian Centre for Electromagnetic Bioeffects Research (ACEBR), Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong NSW 2522, Australia.
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne VIC 3004, Australia.
| | - Adam Verrender
- Australian Centre for Electromagnetic Bioeffects Research (ACEBR), Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong NSW 2522, Australia.
| | - Anna Dalecki
- Australian Centre for Electromagnetic Bioeffects Research (ACEBR), Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong NSW 2522, Australia.
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne VIC 3004, Australia.
| | - Catriona A Burdon
- Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong NSW 2522, Australia.
| | - Kyoko Tagami
- Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong NSW 2522, Australia.
| | - Joonhee Park
- Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong NSW 2522, Australia.
| | - Nigel A S Taylor
- Australian Centre for Electromagnetic Bioeffects Research (ACEBR), Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong NSW 2522, Australia.
- Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong NSW 2522, Australia.
| | - Rodney J Croft
- Australian Centre for Electromagnetic Bioeffects Research (ACEBR), Illawarra Health and Medical Research Institute, School of Psychology, University of Wollongong, Northfields Ave, Wollongong NSW 2522, Australia.
- Centre for Population Health Research on Electromagnetic Energy (PRESEE), School of Public Health and Preventive Medicine, Monash University, Melbourne VIC 3004, Australia.
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Lundgren Kownacki K, Gao C, Kuklane K, Wierzbicka A. Heat Stress in Indoor Environments of Scandinavian Urban Areas: A Literature Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E560. [PMID: 30769945 PMCID: PMC6406735 DOI: 10.3390/ijerph16040560] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/05/2019] [Accepted: 02/10/2019] [Indexed: 01/02/2023]
Abstract
Climate change increases the risks of heat stress, especially in urban areas where urban heat islands can develop. This literature review aims to describe how severe heat can occur and be identified in urban indoor environments, and what actions can be taken on the local scale. There is a connection between the outdoor and the indoor climate in buildings without air conditioning, but the pathways leading to the development of severe heat levels indoors are complex. These depend, for example, on the type of building, window placement, the residential area's thermal outdoor conditions, and the residents' influence and behavior. This review shows that only few studies have focused on the thermal environment indoors during heat waves, despite the fact that people commonly spend most of their time indoors and are likely to experience increased heat stress indoors in the future. Among reviewed studies, it was found that the indoor temperature can reach levels 50% higher in °C than the outdoor temperature, which highlights the importance of assessment and remediation of heat indoors. Further, most Heat-Health Warning Systems (HHWS) are based on the outdoor climate only, which can lead to a misleading interpretation of the health effects and associated solutions. In order to identify severe heat, six factors need to be taken into account, including air temperature, heat radiation, humidity, and air movement as well as the physical activity and the clothes worn by the individual. Heat stress can be identified using a heat index that includes these six factors. This paper presents some examples of practical and easy to use heat indices that are relevant for indoor environments as well as models that can be applied in indoor environments at the city level. However, existing indexes are developed for healthy workers and do not account for vulnerable groups, different uses, and daily variations. As a result, this paper highlights the need for the development of a heat index or the adjustment of current thresholds to apply specifically to indoor environments, its different uses, and vulnerable groups. There are several actions that can be taken to reduce heat indoors and thus improve the health and well-being of the population in urban areas. Examples of effective measures to reduce heat stress indoors include the use of shading devices such as blinds and vegetation as well as personal cooling techniques such as the use of fans and cooling vests. Additionally, the integration of innovative Phase Change Materials (PCM) into facades, roofs, floors, and windows can be a promising alternative once no negative health and environmental effects of PCM can be ensured.
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Affiliation(s)
- Karin Lundgren Kownacki
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
| | - Chuansi Gao
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
| | - Kalev Kuklane
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
| | - Aneta Wierzbicka
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
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Vagedes J, Helmert E, Kuderer S, Müller V, Voege P, Szőke H, Valentini J, Joos S, Kohl M, Andrasik F. Effects of Footbaths with Mustard, Ginger, or Warm Water Only on Objective and Subjective Warmth Distribution in Healthy Subjects: A Randomized Controlled Trial. Complement Ther Med 2018; 41:287-294. [PMID: 30477855 DOI: 10.1016/j.ctim.2018.09.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To analyze the short-term thermogenic effects of footbaths with warm water alone (WA) versus when combined with medicinal powders. DESIGN Randomized controlled trial with cross-over. INTERVENTIONS AND OUTCOMES Seventeen healthy volunteers (mean age 22.1 years, SD = 2.4; 11 female) received three footbaths with WA or WA combined with mustard (MU) or ginger (GI) in a randomized order. Self-perceived warmth (Herdecke warmth perception questionnaire) and actual skin temperatures (thermography) were assessed before (t0), immediately after footbaths (t1), and 10 minutes later (t2). The primary outcome was perceived warmth in the feet. Secondary outcomes were warmth perception in the face, hands and overall, as well as actual skin temperature in the feet, face, and hands. RESULTS Perceived warmth at the feet (primary outcome) increased significantly (all p's < .001) for MU and GI at t1 as well as for GI at t2 when compared to t0 with high effect sizes. At t2, GI differed significantly from WA (p < .001) and MU (p = .048). With regards to the secondary measures of outcome, no significant effects were seen for perceived warmth at the face or hands. Overall warmth was significantly higher at t1 compared to t0 (p = .01). Thermography assessments of skin temperature at the feet at t1 increased after all conditions (p < .001). No effects were seen in the face. At the hands, temperature decreased at t1 (p = .02) and t2 compared to t0 (p < .001). CONCLUSION The present study provides preliminary evidence that mustard and ginger increase warmth perception at the feet more than warm water alone, with only the effects for GI enduring at the brief follow-up.
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Affiliation(s)
- J Vagedes
- University of Tuebingen, Children's Hospital, Tuebingen, Germany; ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany.
| | - E Helmert
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - S Kuderer
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - V Müller
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - P Voege
- ARCIM Institute (Academic Research in Complementary and Integrative Medicine), Filderstadt, Germany
| | - H Szőke
- University of Pécs, Department of CAM, Pécs, Hungary
| | - J Valentini
- University of Tuebingen, Institute of General Practice and Interprofessional Care, Tuebingen, Germany
| | - S Joos
- University of Tuebingen, Institute of General Practice and Interprofessional Care, Tuebingen, Germany
| | - M Kohl
- University Furtwangen, Institute of Precision Medicine, Villingen-Schwenningen, Germany
| | - F Andrasik
- University of Memphis, Department of Psychology, Memphis, TN, USA
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Filingeri D, Zhang H, Arens EA. Thermosensory micromapping of warm and cold sensitivity across glabrous and hairy skin of male and female hands and feet. J Appl Physiol (1985) 2018; 125:723-736. [DOI: 10.1152/japplphysiol.00158.2018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The ability of hands and feet to convey skin thermal sensations is an important contributor to our experience of the surrounding world. Surprisingly, the detailed topographical distribution of warm and cold thermosensitivity across hands and feet has not been mapped, although sensitivity maps exist for touch and pain. Using a recently developed quantitative sensory test, we mapped warm and cold thermosensitivity of 103 skin sites over glabrous and hairy skin of hands and feet in male (M; 30.2 ± 5.8 yr) and female (F; 27.7 ± 5.1 yr) adults matched for body surface area (M: 1.77 ± 0.2 m2; F: 1.64 ± 0.1 m2; P = 0.155). Findings indicated that warm and cold thermosensitivity varies by fivefold across glabrous and hairy skin of hands and feet and that hands (warm/cold sensitivity: 1.25/2.14 vote/°C) are twice as sensitive as the feet (warm/cold sensitivity: 0.51/0.99 vote/°C). Opposite to what is known for touch and pain sensitivity, we observed a characteristic distal-to-proximal increase in thermosensitivity over both hairy and glabrous skin (i.e., from fingers and toes to body of hands and feet), and found that hairy skin is more sensitive than glabrous. Finally, we show that body surface area-matched men and women presented small differences in thermosensitivity and that these differences are constrained to glabrous skin only. Our high-density thermosensory micromapping provides the most detailed thermosensitivity maps of hands and feet in young adults available to date. These maps offer a window into peripheral and central mechanisms of thermosensory integration in humans and will help guide future developments in smart skin and sensory neuroprostheses, in wearable, energy-efficient personal comfort systems, and in sport and protective clothing. NEW & NOTEWORTHY We provide the most detailed thermosensitivity maps across glabrous and hairy skin of hands and feet in men and women available to date. Our maps show that thermosensitivity varies by fivefold across hands and feet, distal regions (e.g., fingers, toes) are less sensitive than proximal (e.g., palm, sole), hands are twice as sensitive as feet, and men and women present small thermosensitivity differences. These findings will help guide developments in sensory neuroprostheses, wearable comfort systems, and sport/protective clothing.
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Affiliation(s)
- Davide Filingeri
- THERMOSENSELAB, Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
- Center for the Built Environment, University of California at Berkeley, Berkeley, California
| | - Hui Zhang
- Center for the Built Environment, University of California at Berkeley, Berkeley, California
| | - Edward A. Arens
- Center for the Built Environment, University of California at Berkeley, Berkeley, California
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45
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McGarr GW, Hodges GJ, Mallette MM, Cheung SS. Ischemia-reperfusion injury alters skin microvascular responses to local heating of the index finger. Microvasc Res 2018; 118:12-19. [DOI: 10.1016/j.mvr.2018.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 02/06/2018] [Accepted: 02/09/2018] [Indexed: 10/18/2022]
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46
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Ruddock A, Robbins B, Tew G, Bourke L, Purvis A. Practical Cooling Strategies During Continuous Exercise in Hot Environments: A Systematic Review and Meta-Analysis. Sports Med 2018; 47:517-532. [PMID: 27480762 PMCID: PMC5309298 DOI: 10.1007/s40279-016-0592-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Background Performing exercise in thermally stressful environments impairs exercise capacity and performance. Cooling during exercise has the potential to attenuate detrimental increases in body temperature and improve exercise capacity and performance. Objective The objective of this review was to assess the effectiveness of practical cooling strategies applied during continuous exercise in hot environments on body temperature, heart rate, whole body sweat production, rating of perceived exertion (RPE), thermal perception and exercise performance. Methods Electronic database searches of MEDLINE, SPORTDiscus, Scopus and Physiotherapy Evidence Database (PEDro) were conducted using medical subject headings, indexing terms and keywords. Studies were eligible if participants were defined as ‘healthy’, the exercise task was conducted in an environment ≥25 °C, it used a cooling strategy that would be practical for athletes to use during competition, cooling was applied during a self-paced or fixed-intensity trial, participants exercised continuously, and the study was a randomised controlled trial with the comparator either a thermoneutral equivalent or no cooling. Data for experimental and comparator groups were meta-analysed and expressed as a standardised mean difference and 95 % confidence interval. Results Fourteen studies including 135 participants met the eligibility criteria. Confidence intervals for meta-analysed data included beneficial and detrimental effects for cooling during exercise on core temperature, mean skin temperature, heart rate and sweat production during fixed-intensity exercise. Cooling benefited RPE and thermal perception during fixed-intensity exercise and improved self-paced exercise performance. Conclusion Cooling during fixed-intensity exercise, particularly before a self-paced exercise trial, improves endurance performance in hot environments by benefiting RPE and thermal perception, but does not appear to attenuate increases in body temperature.
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Affiliation(s)
- Alan Ruddock
- Centre for Sport and Exercise Science, Sheffield Hallam University, A016 Collegiate Hall, Sheffield, S10 2BP, UK.
| | - Brent Robbins
- Centre for Sport and Exercise Science, Sheffield Hallam University, A016 Collegiate Hall, Sheffield, S10 2BP, UK
| | - Garry Tew
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Room 244 Northumberland Building, Newcastle upon Tyne, NE1 8ST, UK
| | - Liam Bourke
- Centre for Sport and Exercise Science, Sheffield Hallam University, A121 Collegiate Hall, Sheffield, S10 2BP, UK
| | - Alison Purvis
- Faculty of Health and Wellbeing, Sheffield Hallam University, F616 Robert Winston Building, Sheffield, S10 2BP, UK
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Bischof JC, Diller KR. From Nanowarming to Thermoregulation: New Multiscale Applications of Bioheat Transfer. Annu Rev Biomed Eng 2018. [PMID: 29865870 DOI: 10.1146/annurev‐bioeng‐071516‐044532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review explores bioheat transfer applications at multiple scales from nanoparticle (NP) heating to whole-body thermoregulation. For instance, iron oxide nanoparticles are being used for nanowarming, which uniformly and quickly rewarms 50-80-mL (≤5-cm-diameter) vitrified systems by coupling with radio-frequency (RF) fields where standard convective warming fails. A modification of this approach can also be used to successfully rewarm cryopreserved fish embryos (∼0.8 mm diameter) by heating previously injected gold nanoparticles with millisecond pulsed laser irradiation where standard convective warming fails. Finally, laser-induced heating of gold nanoparticles can improve the sensitivity of lateral flow assays (LFAs) so that they are competitive with laboratory tests such as the enzyme-linked immunosorbent assay. This approach addresses the main weakness of LFAs, which are otherwise the cheapest, easiest, and fastest to use point-of-care diagnostic tests in the world. Body core temperature manipulation has now become possible through selective thermal stimulation (STS) approaches. For instance, simple and safe heating of selected areas of the skin surface can open arteriovenous anastomosis flow in glabrous skin when it is not already established, thereby creating a convenient and effective pathway to induce heat flow between the body core and environment. This has led to new applications of STS to increase or decrease core temperatures in humans and animals to assist in surgery (perioperative warming), to aid ischemic stress recovery (cooling), and even to enhance the quality of sleep. Together, these multiscale applications of nanoparticle heating and thermoregulation point to dramatic opportunities for translation and impact in these prophylactic, preservative, diagnostic, and therapeutic applications of bioheat transfer.
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Affiliation(s)
- John C Bischof
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA;
| | - Kenneth R Diller
- Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
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48
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Sixtus RP, Galland BC, Cotter JD. Foot cooling does not improve vigilance but may transiently reduce sleepiness. J Sleep Res 2018; 28:e12701. [PMID: 29749043 DOI: 10.1111/jsr.12701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 11/27/2022]
Abstract
Temperature of the skin (TSk ) and core (TC ) play key roles in sleep-wake regulation. The diurnal combination of low TSk and high TC facilitates alertness, whereas the transition to high TSk and low TC correlates with sleepiness. Sleepiness and deteriorating vigilance are induced with peripheral warming, whereas peripheral cooling appears to transiently improve vigilance in narcolepsy. This study aimed to test the hypothesis that foot cooling would maintain vigilance during extended wakefulness in healthy adults. Nine healthy young adult participants with habitually normal sleep completed three constant-routine trials in randomized crossover order. Trials began at 22:30 hours, and involved continuous mild foot cooling (30°C), moderate foot cooling (25°C) or no foot cooling, while undertaking six × 10-min Psychomotor Vigilance Tasks and seven × 7-min Karolinska Drowsiness Tasks, interspersed with questionnaires of sleepiness and thermal perceptions. Foot temperatures in control, mild and moderate cooling averaged 34.5 ± 0.5°C, 30.8 ± 0.2°C and 26.4 ± 0.1°C (all p < .01), while upper-limb temperatures remained stable (34-35°C) and TC declined (approximately -0.12°C per hr) regardless of trial (p = .84). Foot cooling did not improve vigilance (repeated-measures-ANOVA interaction for response speed: p = .45), but transiently reduced subjective sleepiness (-0.8 ± 0.8; p = .004). Participants felt cooler throughout cooling trials, but thermal comfort was unaffected (p = .43), as were almost all Karolinska Drowsiness Tasks' encephalographic parameters. In conclusion, mild or moderate cooling of the feet did not attenuate declines in vigilance or core temperature of healthy young adults during the period of normal sleep onset and early sleep, and any effect on sleepiness was small and transient.
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Affiliation(s)
- Ryan P Sixtus
- School of Physical Education, Sport and Exercise Sciences, Division of Sciences, University of Otago, Dunedin, New Zealand
| | - Barbara C Galland
- Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, Division of Sciences, University of Otago, Dunedin, New Zealand
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Payne S, Macintosh A, Stock J. The influence of digit size and proportions on dexterity during cold exposure. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:875-883. [PMID: 29676438 DOI: 10.1002/ajpa.23486] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/28/2018] [Accepted: 03/30/2018] [Indexed: 01/27/2023]
Abstract
OBJECTIVES The current study investigated whether size and proportions of the hands and digits affect dexterity during severe cold exposure. As wide hands are known to lose less heat than narrow hands, and narrow digits are associated with greater dexterity, this study aimed to test whether there was a direct trade-off between dexterity and thermoregulation that shapes hand morphology. METHODS Participants (25 women, 15 men) carried out the Purdue Pegboard test before and after a 3-min ice-water immersion of the hand. Their hand length, hand width, digit lengths, and digit widths were measured using standard anthropometric methods. RESULTS Wide first and third digits associated with significantly reduced dexterity after immersion relative to individuals with narrower first and third digits. Second digit width positively correlated with average digit temperature after immersion. Hand length and hand width did not influence dexterity. CONCLUSION The current study suggests that digit width influences dexterity in cold conditions, reflecting patterns found at room temperature. Hand and digit morphology may be the product of two significant constraints on the hand: dexterity and thermoregulation. In cold conditions, hand morphology appears to be predominantly constrained by thermal stress, at the expense of dexterity. This may have important implications for interpreting the morphology of extinct and extant hominins.
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Affiliation(s)
- Stephanie Payne
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom
| | - Alison Macintosh
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom
| | - Jay Stock
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom.,Department of Anthropology, University of Western Ontario, London, Ontario, N6A 5C2, Canada
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50
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Payne S, Macintosh A, Stock J. The thermoregulatory function of the human hand: How do palm and digit proportions affect heat loss? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:803-811. [PMID: 29603137 DOI: 10.1002/ajpa.23469] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 11/12/2022]
Abstract
OBJECTIVES The current study assessed whether ecogeographical patterns seen in hand proportions correlate with heat loss directly. Using a brief severe cold immersion experiment on the hand, the influence of hand and digit dimensions on heat loss was evaluated. MATERIALS AND METHODS A sample of 113 living individuals were tested. Two-dimensional and three-dimensional scanning techniques were used to assess hand and digit dimensions. Thermal imaging analysis was used to quantify heat loss during a 3-min ice-water immersion of the hands. RESULTS When body size was accounted for, hand width and digit length relative to total hand length were significant predictors of heat loss from the hand. DISCUSSION The current study provides empirical evidence to support the link between thermodynamic principles relating to surface area-to-volume ratio, and ecogeographical patterns associated with temperature.
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Affiliation(s)
- Stephanie Payne
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom
| | - Alison Macintosh
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom
| | - Jay Stock
- PAVE Research Group, Department of Archaeology, University of Cambridge, Cambridgeshire, CB2 3EX, United Kingdom.,Department of Anthropology, University of Western Ontario, London, Ontario, N6A 5C2, Canada
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