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Su Y, Hoekstra SP, Leicht CA. Hot water immersion is associated with higher thermal comfort than dry passive heating for a similar rise in rectal temperature and plasma interleukin-6 concentration. Eur J Appl Physiol 2024; 124:1109-1119. [PMID: 37870668 PMCID: PMC10954860 DOI: 10.1007/s00421-023-05336-8] [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: 05/16/2023] [Accepted: 09/28/2023] [Indexed: 10/24/2023]
Abstract
PURPOSE To compare the perceptual responses and interleukin-6 (IL-6) concentration following rectal temperature-matched dry heat exposure (DH) and hot water immersion (HWI). METHODS Twelve healthy young adults (BMI 23.5 ± 3.6 kg/m2; age: 25.8 ± 5.7 years) underwent 3 trials in randomised order: DH (air temperature 68.9 °C), HWI (water temperature 37.5 °C), and thermoneutral dry exposure (CON, air temperature 27.3 °C). Blood samples to determine IL-6 plasma concentration were collected; basic affect and thermal comfort, rectal and skin temperature (Tskin) were assessed throughout the intervention. RESULTS Rectal temperature (Trec) did not differ between DH (end temperature 38.0 ± 0.4 °C) and HWI (37.9 ± 0.2 °C, P = 0.16), but was higher compared with CON (37.0 ± 0.3 °C; P ≤ 0.004). Plasma IL-6 concentration was similar after DH (pre to post: 0.8 ± 0.5 to 1.4 ± 1.5 pg·ml-1) and HWI (0.5 ± 0.2 to 0.9 ± 0.6 pg·ml-1; P = 0.46), but higher compared with CON (0.6 ± 0.5 to 0.6 ± 0.4 pg·ml-1; P = 0.01). At the end of the intervention, basic affect and thermal comfort were most unfavourable during DH (Basic affect; DH: - 0.7 ± 2.9, HWI: 0.8 ± 1.9, CON 1.9 ± 1.9, P ≤ 0.004; Thermal comfort; 2.6 ± 0.8, HWI: 1.4 ± 0.9 and CON: 0.2 ± 0.4; P ≤ 0.004). Mean Tskin was highest for DH, followed by HWI, and lowest for CON (DH: 38.5 ± 1.3 °C, HWI: 36.2 ± 0.5 °C, CON: 31.6 ± 0.7 °C, P < 0.001). CONCLUSION The IL-6 response did not differ between DH and HWI when matched for the elevation in Trec. However, thermal comfort was lower during DH compared to HWI, which may be related to the higher Tskin during DH.
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Affiliation(s)
- Yunuo Su
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK
| | - Sven P Hoekstra
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK
- Department of Rehabilitation Medicine, University of Texas Health Science Center at San Antonio, San Antonio, USA
| | - Christof A Leicht
- Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK.
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Zhou W, Yang M, Yu X, Peng Y, Fan C, Xu D, Xiao Q. Enhancing thermal comfort prediction in high-speed trains through machine learning and physiological signals integration. J Therm Biol 2024; 121:103828. [PMID: 38604115 DOI: 10.1016/j.jtherbio.2024.103828] [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: 11/06/2023] [Revised: 02/02/2024] [Accepted: 02/18/2024] [Indexed: 04/13/2024]
Abstract
Heating, Ventilation, and Air Conditioning (HVAC) systems in high-speed trains (HST) are responsible for consuming approximately 70% of non-operational energy sources, yet they frequently fail to ensure provide adequate thermal comfort for the majority of passengers. Recent advancements in portable wearable sensors have opened up new possibilities for real-time detection of occupant thermal comfort status and timely feedback to the HVAC system. However, since occupant thermal comfort is subjective and cannot be directly measured, it is generally inferred from thermal environment parameters or physiological signals of occupants within the HST compartment. This paper presents a field test conducted to assess the thermal comfort of occupants within HST compartments. Leveraging physiological signals, including skin temperature, galvanic skin reaction, heart rate, and ambient temperature, we propose a Predicted Thermal Comfort (PTC) model for HST cabin occupants and establish an intelligent regulation model for the HVAC system. Nine input factors, comprising physiological signals, individual physiological characteristics, compartment seating, and ambient temperature, were formulated for the PTS model. In order to obtain an efficient and accurate PTC prediction model for HST cabin occupants, we compared the accuracy of different subsets of features trained by Machine Learning (ML) models of Random Forest, Decision Tree, Vector Machine and K-neighbourhood. We divided all the predicted feature values into four subsets, and did hyperparameter optimisation for each ML model. The HST compartment occupant PTC prediction model trained by Random Forest model obtained 90.4% Accuracy (F1 macro = 0.889). Subsequent sensitivity analyses of the best predictive models were then performed using SHapley Additive explanation (SHAP) and data-based sensitivity analysis (DSA) methods. The development of a more accurate and operationally efficient thermal comfort prediction model for HST occupants allows for precise and detailed feedback to the HVAC system. Consequently, the HVAC system can make the most appropriate and effective air supply adjustments, leading to improved satisfaction rates for HST occupant thermal comfort and the avoidance of energy wastage caused by inaccurate and untimely predictive feedback.
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Affiliation(s)
- Wenjun Zhou
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China.
| | - Mingzhi Yang
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China.
| | - Xiaoyan Yu
- Faculty of Mathematics and Natural Sciences, Humboldt University of Berlin, Berlin, Germany.
| | - Yong Peng
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China; National & Local Joint Engineering Research Center of Safety Technology for Rail Vehicle, Central South University, Changsha, 410000, China.
| | - Chaojie Fan
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China.
| | - Diya Xu
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China.
| | - Qiang Xiao
- Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, 410000, China.
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Zou Y, Maillet B, Brochard L, Coussot P. Unveiling moisture transport mechanisms in cellulosic materials: Vapor vs. bound water. PNAS NEXUS 2024; 3:pgad450. [PMID: 38187807 PMCID: PMC10768996 DOI: 10.1093/pnasnexus/pgad450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/12/2023] [Indexed: 01/09/2024]
Abstract
Natural textiles, hair, paper, wool, or bio-based walls possess the remarkable ability to store humidity from sweat or the environment through "bound water" absorption within nanopores, constituting up to 30% of their dry mass. The knowledge of the induced water transfers is pivotal for advancing industrial processes and sustainable practices in various fields such as wood drying, paper production and use, moisture transfers in clothes or hair, humidity regulation of bio-based construction materials, etc. However, the transport and storage mechanisms of this moisture remain poorly understood, with modeling often relying on an assumption of dominant vapor transport with an unknown diffusion coefficient. Our research addresses this knowledge gap, demonstrating the pivotal role of bound water transport within interconnected fiber networks. Notably, at low porosity, bound water diffusion dominates over vapor diffusion. By isolating diffusion processes and deriving diffusion coefficients through rigorous experimentation, we establish a comprehensive model for moisture transfer. Strikingly, our model accurately predicts the evolution of bound water's spatial distribution for a wide range of sample porosities, as verified through magnetic resonance imaging. Showing that bound water transport can be dominant over vapor transport, this work offers a change of paradigm and unprecedented control over humidity-related processes.
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Affiliation(s)
- Yuliang Zou
- Laboratoire Navier, Univ. Gustave Eiffel, ENPC, CNRS, 77420 Champs sur Marne, France
| | - Benjamin Maillet
- Laboratoire Navier, Univ. Gustave Eiffel, ENPC, CNRS, 77420 Champs sur Marne, France
| | - Laurent Brochard
- Laboratoire Navier, Univ. Gustave Eiffel, ENPC, CNRS, 77420 Champs sur Marne, France
| | - Philippe Coussot
- Laboratoire Navier, Univ. Gustave Eiffel, ENPC, CNRS, 77420 Champs sur Marne, France
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de Korte JQ, Eijsvogels TMH, Hopman MTE, Bongers CCWG. Thermoregulatory, Cardiovascular and Perceptual Responses of Spectators of a Simulated Football Match in Hot and Humid Environmental Conditions. Sports (Basel) 2023; 11:78. [PMID: 37104152 PMCID: PMC10140829 DOI: 10.3390/sports11040078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/17/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
Major sporting events are often scheduled in thermally challenging environments. The heat stress may impact athletes but also spectators. We examined the thermal, cardiovascular, and perceptual responses of spectators watching a football match in a simulated hot and humid environment. A total of 48 participants (43 ± 9 years; n = 27 participants <50 years and n = 21 participants ≥50 years, n = 21) watched a 90 min football match in addition to a 15 min baseline and 15 min halftime break, seated in an environmental chamber (Tair = 31.9 ± 0.4 °C; RH = 76 ± 4%). Gastrointestinal temperature (Tgi), skin temperature (Tskin), and heart rate (HR) were measured continuously throughout the match. Mean arterial pressure (MAP) and perceptual parameters (i.e., thermal sensation and thermal comfort) were scored every 15 min. Tri (37.3 ± 0.4 °C to 37.4 ± 0.3 °C, p = 0.11), HR (76 ± 15 bpm to 77 ± 14 bpm, p = 0.96) and MAP (97 ± 10 mm Hg to 97 ± 10 mm Hg, p = 0.67) did not change throughout the match. In contrast, an increase in Tskin (32.9 ± 0.8 °C to 35.4 ± 0.3 °C, p < 0.001) was found. Further, 81% of participants reported thermal discomfort and 87% a (slightly) warm thermal sensation at the end of the match. Moreover, the thermal or cardiovascular responses were not affected by age (all p-values > 0.05). Heat stress induced by watching a football match in simulated hot and humid conditions does not result in substantial thermal or cardiovascular strain, whereas a significant perceptual strain was observed.
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Affiliation(s)
- Johannus Q. de Korte
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Thijs M. H. Eijsvogels
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Maria T. E. Hopman
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Coen C. W. G. Bongers
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
- School of Sport and Exercise, Health Promotion & Performance, HAN University of Applied Sciences, 6525AJ Nijmegen, The Netherlands
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5
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Jenkins EJ, Campbell HA, Lee JKW, Mündel T, Cotter JD. Delineating the impacts of air temperature and humidity for endurance exercise. Exp Physiol 2023; 108:207-220. [PMID: 36537856 PMCID: PMC10103870 DOI: 10.1113/ep090969] [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: 10/25/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
NEW FINDINGS What is the central question of this study? What are the independent effects of air temperature and humidity on performance, physiological and perceptual responses during endurance exercise? What is the main finding and its importance? When examined independently, elevated air temperature increased heat strain and impaired aerobic exercise performance, but to a lesser extent than has been reported previously. These findings highlight the importance of absolute humidity relative to temperature when exercising or working under severe heat stress. ABSTRACT Many studies have reported that ambient heat stress increases physiological and perceptual strain and impairs endurance exercise, but effects of air temperature per se remain almost unexamined. Most studies have used matched relative humidity, thereby exponentially increasing absolute humidity (water content in air) concurrently with temperature. Absolute (not relative) humidity governs evaporative rate and is more important at higher work rates and air temperatures. Therefore, we examined the independent effects of air temperature and humidity on performance, thermal, cardiovascular and perceptual measures during endurance exercise. Utilizing a crossover design, 14 trained participants (7 females) completed 45 min fixed-intensity cycling (70%V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ ) followed by a 20-km time trial in each of four environments: three air temperatures at matched absolute humidity (Cool, 18°C; Moderate, 27°C; and Hot, 36°C; at 1.96 kPa, air velocity ∼4.5 m/s), and one at elevated humidity (Hot Humid, 36°C at 3.92 kPa). Warmer air caused warmer skin (0.5°C/°C; P < 0.001), higher heart rate (1 bpm/°C; P < 0.001), sweat rate (0.04 l/h/°C; P < 0.001) and thermal perceptions during fixed-intensity exercise, but minimally affected core temperature (<0.01°C/°C; P = 0.053). Time-trial performance was comparable between Cool and Moderate (95% CI: -1.4, 5.9%; P = 0.263), but 3.6-6% slower in Hot (95% CI: ±2.4%; P ≤ 0.006). Elevated humidity increased core temperature (P < 0.001), perceived temperature and discomfort but not skin temperature or heart rate, and reduced mean blood pressure (P = 0.046) during fixed-intensity exercise. Elevated humidity impaired time-trial performance by 3.4% (95% CI: ±2.2%; P = 0.006). In conclusion, these findings quantify the importance of absolute humidity alongside air temperature when exercising under severe heat stress.
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Affiliation(s)
- Elliott J. Jenkins
- School of Physical EducationSport and Exercise SciencesUniversity of OtagoDunedinNew Zealand
- Cardiff School of Sport and Health SciencesCardiff Metropolitan UniversityCardiffUK
| | - Holly A. Campbell
- Department of Surgical SciencesDunedin School of MedicineUniversity of OtagoDunedinNew Zealand
| | - Jason K. W. Lee
- Department of PhysiologyNational University of SingaporeSingapore
- Heat Resilience and Performance CentreYong Loo Lin School of MedicineNational University of SingaporeSingapore
- Human Potential Translational Research ProgrammeYong Loo Lin School of MedicineNational University of SingaporeSingapore
- Department of PhysiologyYong Loo Lin School of MedicineNational University of SingaporeSingapore
- Campus for Research Excellence and Technological Enterprise (CREATE)Singapore
| | - Toby Mündel
- School of SportExercise and NutritionMassey UniversityPalmerston NorthNew Zealand
| | - James D. Cotter
- School of Physical EducationSport and Exercise SciencesUniversity of OtagoDunedinNew Zealand
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6
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Bröde P, Aerts JM, De Bruyne G, Mayor TS, Annaheim S, Fiala D, Kuklane K. A modelling framework for local thermal comfort assessment related to bicycle helmet use. J Therm Biol 2023; 112:103457. [PMID: 36796903 DOI: 10.1016/j.jtherbio.2022.103457] [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: 10/28/2022] [Revised: 12/22/2022] [Accepted: 12/28/2022] [Indexed: 01/02/2023]
Abstract
Thermal discomfort due to accumulated sweat increasing head skin wettedness may contribute to low wearing rates of bicycle helmets. Using curated data on human head sweating and helmet thermal properties, a modelling framework for the thermal comfort assessment of bicycle helmet use is proposed. Local sweat rates (LSR) at the head were predicted as the ratio to the gross sweat rate (GSR) of the whole body or by sudomotor sensitivity (SUD), the change in LSR per change in body core temperature (Δtre). Combining those local models with Δtre and GSR output from thermoregulation models, we simulated head sweating depending on the characteristics of the thermal environment, clothing, activity, and exposure duration. Local thermal comfort thresholds for head skin wettedness were derived in relation to thermal properties of bicycle helmets. The modelling framework was supplemented by regression equations predicting the wind-related reductions in thermal insulation and evaporative resistance of the headgear and boundary air layer, respectively. Comparing the predictions of local models coupled with different thermoregulation models to LSR measured at the frontal, lateral and medial head under bicycle helmet use revealed a large spread in LSR predictions predominantly determined by the local models and the considered head region. SUD tended to overestimate frontal LSR but performed better for lateral and medial head regions, whereas predictions by LSR/GSR ratios were lower and agreed better with measured frontal LSR. However, even for the best models root mean squared prediction errors exceeded experimental SD by 18-30%. From the high correlation (R > 0.9) of skin wettedness comfort thresholds with local sweating sensitivity reported for different body regions, we derived a threshold value of 0.37 for head skin wettedness. We illustrate the application of the modelling framework using a commuter-cycling scenario, and discuss its potential as well as the needs for further research.
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Affiliation(s)
- Peter Bröde
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo)(1), Ardeystr. 67, 44139 Dortmund, Germany.
| | | | - Guido De Bruyne
- Department of Product Development, Faculty of Design Sciences, University of Antwerp, Belgium; Lazer Sport NV, Mechelen, Belgium
| | - Tiago Sotto Mayor
- Transport Phenomena Research Centre (CEFT), Engineering Faculty of Porto University, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; Associate Laboratory in Chemical Engineering (ALiCE), Engineering Faculty of Porto University, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Simon Annaheim
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
| | - Dusan Fiala
- Ergonsim - Human Thermal Modelling, Messstetten, Germany
| | - Kalev Kuklane
- Netherlands Institute for Public Safety (NIPV), Zoetermeer, The Netherlands
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7
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Kato I, Masuda Y, Nagashima K. Characteristics of wet perception during the static touch of moist paper by the index fingertip alongside thermal stimulus application. Physiol Behav 2023; 258:114033. [PMID: 36395881 DOI: 10.1016/j.physbeh.2022.114033] [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: 09/10/2022] [Revised: 11/11/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022]
Abstract
Several factors have been reported to affect the perception of wetness. In the present study, we aimed to examine how wet perception changes when the factors related to thermal and/or wetness stimuli are modulated. First, the percentage of participants experiencing wet perception among filter papers with different water contents (0.00, 3.75, 7.50, 11.25, 15.00, and 18.75 µg/cm2, corresponding to 0.00, 0.18, 0.37, 0.55,0.73 and 0.91 µg/mm3) was evaluated during static touch by the right index finger pad. The stimulus temperature was maintained at 30 °C. Second, the wet perception of paper with a water content of 18.75 µg/cm2 was evaluated at stimulus temperature of 20 °C, 25 °C, 30 °C, 35 °C, and 40 °C. In the first experiment, the percentage of participants experiencing wet perception elevated with the increasing water content; however, the percentage plateaued at 11.25 µg/cm2 of water (68.1 ± 25.5%). In the second experiment, when the stimulus temperature was < 30 °C, the wet perception increased as the stimulation temperature decreased. However, the wet perception reached a plateau at a stimulation temperature ≥30 °C. Participants experienced wet perception more consistently as the water content increased when the stimulus temperature was 30 ˚C. The effect of temperature on wet perception was limited to the stimulus temperature of <30 °C at which cold sensation was induced. However, no clear relationship between stimulus temperature and wet perception was observed when the stimulus temperature was ≥30 ˚C at which warm/hot sensation was induced.
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Affiliation(s)
- Issei Kato
- Graduate School of Human Sciences, Waseda University; Mikajima 2-579-15, 359-1192, Tokorozawa, Saitama, Japan; Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University; Mikajima 2-579-15, 359-1192, Tokorozawa, Saitama, Japan
| | - Yuta Masuda
- Graduate School of Human Sciences, Waseda University; Mikajima 2-579-15, 359-1192, Tokorozawa, Saitama, Japan; Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University; Mikajima 2-579-15, 359-1192, Tokorozawa, Saitama, Japan
| | - Kei Nagashima
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University; Mikajima 2-579-15, 359-1192, Tokorozawa, Saitama, Japan.
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Sedilla KB, Maeda T. Autonomic thermoregulatory responses and subjective thermal perceptions upon the initiation of thermal behavior among resting humans in hot and humid environment. J Physiol Anthropol 2022; 41:35. [PMID: 36217190 PMCID: PMC9549644 DOI: 10.1186/s40101-022-00308-x] [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: 05/19/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022] Open
Abstract
Background While thermoregulatory behavior is critical for maintaining homeostasis, our knowledge of behavioral thermoeffectors in humid heat is limited compared to the control of autonomic thermoeffectors. The predictions that the frequency and duration of intensified humid heat events are expected to increase in the coming years underline this shortcoming. Therefore, this study aims to elucidate the activation of autonomic thermoregulatory responses and subjective thermal perceptions upon deciding to initiate thermal behavior in a hot and humid environment. Methods Ten young male adults participated in an experimental trial where local cooling was permitted at any time during the behavioral assessment during passive exposure to humid heat. The air temperature and relative humidity were kept at 33\documentclass[12pt]{minimal}
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\begin{document}$$^{\circ }$$\end{document}∘C and 80\documentclass[12pt]{minimal}
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\begin{document}$$\%$$\end{document}%, respectively. Skin temperatures, core body temperature (T\documentclass[12pt]{minimal}
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\begin{document}$$_{\text {core}}$$\end{document}core), and skin blood flow (forearm, upper arm, and upper back) were obtained 120 s preceding thermal behavior. Local sweat rate (forearm and upper arm) and subjective thermal perceptions (neck and whole-body) upon thermal behavior initiation were also recorded. Results Mean skin temperature (\documentclass[12pt]{minimal}
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\begin{document}$${\overline{\mathrm {T}}}_{\text {body}}$$\end{document}T¯body) was also observed (p < 0.001). However, the initiation of thermal behavior is not preceded by an increase in skin blood flow (p\documentclass[12pt]{minimal}
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\begin{document}$$\ge$$\end{document}≥ 0.154) and local sweat rate (p\documentclass[12pt]{minimal}
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\begin{document}$$\ge$$\end{document}≥ 0.169). An increase in thermal discomfort and skin wetness perception was observed (p\documentclass[12pt]{minimal}
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\begin{document}$$\le$$\end{document}≤ 0.048; p\documentclass[12pt]{minimal}
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\begin{document}$$\le$$\end{document}≤ 0.048), while thermal sensation did not differ from the baseline (p\documentclass[12pt]{minimal}
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\begin{document}$$\ge$$\end{document}≥ 0.357). Conclusion These findings suggest that when given the opportunity to behaviorally thermoregulate in a hot and humid environment, changes in skin blood flow and sweat rate are not required for thermal behavior to be initiated in resting humans. Moreover, an increase in \documentclass[12pt]{minimal}
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\begin{document}$$_{\text {core}}$$\end{document}core, which appears to cause an increase in thermal discomfort, precedes thermal behavior. In addition, an increase in \documentclass[12pt]{minimal}
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\begin{document}$$_{\text {core}}$$\end{document}core alone mediate thermal behavior in humid heat. Collectively, the results of this study appear to support the hypothesis that the temporal recruitment of autonomic thermoeffectors follows an orderly manner based on their physiological cost.
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Affiliation(s)
- Keneth B. Sedilla
- grid.177174.30000 0001 2242 4849Department of Design (Human Science International Course), Graduate School of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, 815-8540 Fukuoka, Japan
| | - Takafumi Maeda
- grid.177174.30000 0001 2242 4849Department of Human Life Design and Science, Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, 815-8540 Fukuoka, Japan ,grid.177174.30000 0001 2242 4849Physiological Anthropology Research Center, Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, 815-8540 Fukuoka, Japan
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9
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Wildgoose C, Valenza A, Buoite Stella A, Feka K, Bianco A, Filingeri D. Ageing reduces skin wetness sensitivity across the body. Exp Physiol 2021; 106:2434-2444. [PMID: 34676631 DOI: 10.1113/ep090027] [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: 09/01/2021] [Accepted: 10/14/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Ageing impairs the skin's thermal and tactile sensitivity: does ageing also induce loss of skin wetness sensitivity? What is the main finding and its importance? Older adults show an average 15% loss of skin wetness sensitivity, with this sensory deficit being mediated by a combination of reductions in skin's tactile sensing and hydration status. These findings increase knowledge of wetness sensing mechanisms across the lifespan. ABSTRACT Humans use sensory integration mechanisms to sense skin wetness based on thermal and mechanical cues. Ageing impairs the skin's thermal and tactile sensitivity, yet we lack evidence on whether wetness sensing also changes with ageing. We mapped local skin wetness and temperature sensitivity in response to cold-, neutral- and warm-wet stimuli applied to the forehead, neck, lower back, dorsal foot, index finger and thumb, in 10 Younger (22.4 ± 1.1 years) and 10 Older (58.2 ± 5.1 years) males. We measured local skin temperature and conductance (i.e., a marker of hydration status) at the tested sites, to establish the role of skin's thermal and mechanical parameters in ageing-induced changes in wetness sensing. Irrespective of body site, Older reported overall lower wetness perceptions than Younger across all wet-stimulus temperatures (mean difference: -14.6 mm; 95% CI: -4.3, -24.9; P = 0.008; ∼15% difference). When considering regional wetness sensitivity, the effect of ageing was more pronounced in response to the cold-wet stimulus over the lover back (mean difference Older vs. Younger: -36.8 mm; 95% CI: -68.4, -5.2; P = 0.014; ∼37% difference) and dorsal foot (mean difference: -37.1 mm; 95% CI: -68.7, -5.5; P = 0.013; ∼37% difference). We found no differences between age groups on overall thermal sensations (P = 0.744) nor local skin temperature (P = 0.372); however, we found that Older presented overall lower skin conductance than Younger (mean difference: -1.56 μS; 95% CI: -0.49, -2.62; P = 0.005), which corresponded to an ∼78% reduction in skin hydration. We conclude that skin wetness sensing decreases with ageing primarily due to age-induced changes in skin mechanics and tactile sensitivity.
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Affiliation(s)
- Charlotte Wildgoose
- THERMOSENSELAB, School of Design and Creative Arts, Loughborough University, Loughborough, UK
| | - Alessandro Valenza
- Sport and Exercise Sciences Research Unit, SPPEFF Department, University of Palermo, Palermo, Italy
| | - Alex Buoite Stella
- Clinical Unit of Neurology, Department of Medicine, Surgery and Health Sciences, Trieste University Hospital-ASUGI, University of Trieste, Trieste, Italy
| | - Kaltrina Feka
- Sport and Exercise Sciences Research Unit, SPPEFF Department, University of Palermo, Palermo, Italy
| | - Antonino Bianco
- THERMOSENSELAB, School of Design and Creative Arts, Loughborough University, Loughborough, UK
| | - Davide Filingeri
- THERMOSENSELAB, Skin Health Research Group, School of Health Sciences, University of Southampton, Southampton, UK
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10
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Footwear microclimate and its effects on the microbial community of the plantar skin. Sci Rep 2021; 11:20356. [PMID: 34645918 PMCID: PMC8514438 DOI: 10.1038/s41598-021-99865-x] [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] [Received: 05/07/2021] [Accepted: 09/28/2021] [Indexed: 01/04/2023] Open
Abstract
The association between the footwear microclimate and microbial community on the foot plantar skin was investigated by experiments with three participants. Novel methods were developed for measuring in-shoe temperature and humidity at five footwear regions, as well as the overall ventilation rate inside the footwear. Three types of footwear were tested including casual shoes, running shoes, and perforated shoes for pairwise comparison of footwear microclimate and corresponding microbial community on the skin. The major findings are as follows: (1) footwear types make a significant difference to in-shoe temperature at the instep region with the casual shoes sustaining the warmest of all types; (2) significant differences were observed in local internal absolute humidity between footwear types, with the casual shoes sustaining the highest level of humidity at most regions; (3) the perforated shoes provided the highest ventilation rate, followed by running and casual shoes, and the faster the gait, the larger the discrepancy in ventilation rate between footwear types; (4) the casual shoes seemed to provide the most favorable internal environment for bacterial growth at the distal plantar skin; and (5) the bacterial growth at the distal plantar skin showed a positive linear correlation with the in-shoe temperature and absolute humidity, and a negative linear correlation with the ventilation rate. The ventilation rate seemed to be a more reliable indicator of the bacterial growth. Above all, we can conclude that footwear microclimate varies in footwear types, which makes contributions to the bacterial growth on the foot plantar skin.
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11
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Temel M, Johnson AA, Havenith G, Arnold JT, West AM, Lloyd AB. An examination of five theoretical foundations associated with localized thermosensory testing. Eur J Appl Physiol 2021; 121:1943-1954. [PMID: 33765169 PMCID: PMC8192324 DOI: 10.1007/s00421-021-04670-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/16/2021] [Indexed: 11/05/2022]
Abstract
Purpose To assess five theoretical foundations underlying thermosensory testing using local thermal stimuli. Methods Thermal sensation, discomfort and the confidence of thermal sensation scores were measured in 9 female and 8 male volunteers in response to 17 physical contact temperature stimuli, ranging between 18–42 °C. These were applied to their dorsal forearm and lateral torso, across two sessions. Results Thermal sensation to physical temperature relationships followed a positive linear and sigmoidal fit at both forearm (r2 = 0.91/r2 = 0.91, respectively) and lateral torso (r2 = 0.90/ r2 = 0.91, respectively). Thermal discomfort to physical temperature relationships followed second and third-order fits at both forearm (r2 = 0.33/r2 = 0.34, respectively) and lateral torso (r2 = 0.38/r2 = 0.39, respectively) test sites. There were no sex-related or regional site differences in thermal sensation and discomfort across a wide range of physical contact temperatures. The median confidence of an individual’s thermal sensation rating was measured at 86%. Conclusion The relation between thermal sensation and physical contact temperature was well described by both linear and sigmoidal models, i.e., the distance between the thermal sensation anchors is close to equal in terms of physical temperatures changes for the range studied. Participants rated similar thermal discomfort level in both cold and hot thermal stimuli for a given increase or decrease in physical contact temperature or thermal sensation. The confidence of thermal sensation rating did not depend on physical contact temperature.
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Affiliation(s)
- Mevra Temel
- School of Design and Creative Arts, Loughborough University, Loughborough, UK.,Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK
| | - Andrew A Johnson
- School of Design and Creative Arts, Loughborough University, Loughborough, UK
| | - George Havenith
- School of Design and Creative Arts, Loughborough University, Loughborough, UK.,Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK
| | - Josh T Arnold
- School of Design and Creative Arts, Loughborough University, Loughborough, UK.,Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK
| | - Anna M West
- School of Design and Creative Arts, Loughborough University, Loughborough, UK.,Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK
| | - Alex B Lloyd
- School of Design and Creative Arts, Loughborough University, Loughborough, UK. .,Environmental Ergonomics Research Centre, Loughborough University, Loughborough, UK.
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12
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Local cooling during hot water immersion improves perceptions without inhibiting the acute interleukin-6 response. Eur J Appl Physiol 2021; 121:1581-1591. [PMID: 33646422 PMCID: PMC8144146 DOI: 10.1007/s00421-021-04616-5] [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: 07/17/2020] [Accepted: 02/04/2021] [Indexed: 11/02/2022]
Abstract
PURPOSE Passive elevation of body temperature can induce an acute inflammatory response that has been proposed to be beneficial; however, it can be perceived as uncomfortable. Here, we investigate whether local cooling of the upper body during hot water immersion can improve perception without inhibiting the interleukin-6 (IL-6) response. METHODS Nine healthy male participants (age: 22 ± 1 years, body mass: 83.4 ± 9.4 kg) were immersed up to the waist for three 60-min water immersion conditions: 42 °C hot water immersion (HWI), 42 °C HWI with simultaneous upper-body cooling using a fan (FAN), and 36 °C thermoneutral water immersion (CON). Blood samples to determine IL-6 plasma concentration were collected pre- and post-water immersion; basic affect and thermal comfort were assessed throughout the intervention. RESULTS Plasma IL-6 concentration was higher for HWI and FAN when compared with CON (P < 0.01) and did not differ between HWI and FAN (P = 0.22; pre to post, HWI: 1.0 ± 0.6 to 1.5 ± 0.7 pg·ml-1, FAN: 0.7 ± 0.5 to 1.1 ± 0.5 pg·ml-1, CON: 0.5 ± 0.2 to 0.5 ± 0.2 pg·ml-1). At the end of immersion, basic affect was lowest for HWI (HWI: - 1.8 ± 2.0, FAN: 0.2 ± 1.6, CON 1.0 ± 2.1, P < 0.02); thermal comfort for HWI was in the uncomfortable range (3.0 ± 1.0, P < 0.01 when compared with FAN and CON), whereas FAN (0.7 ± 0.7) and CON (-0.2 ± 0.7) were in the comfortable range. CONCLUSION Local cooling of the upper body during hot water immersion improves basic affect and thermal comfort without inhibiting the acute IL-6 response.
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Abstract
Evaluating and optimising human comfort within the built environment is challenging due to the large number of physiological, psychological and environmental variables that affect occupant comfort preference. Human perception could be helpful to capture these disparate phenomena and interpreting their impact; the challenge is collecting spatially and temporally diverse subjective feedback in a scalable way. This paper presents a methodology to collect intensive longitudinal subjective feedback of comfort-based preference using micro ecological momentary assessments on a smartwatch platform. An experiment with 30 occupants over two weeks produced 4378 field-based surveys for thermal, noise, and acoustic preference. The occupants and the spaces in which they left feedback were then clustered according to these preference tendencies. These groups were used to create different feature sets with combinations of environmental and physiological variables, for use in a multi-class classification task. These classification models were trained on a feature set that was developed from time-series attributes, environmental and near-body sensors, heart rate, and the historical preferences of both the individual and the comfort group assigned. The most accurate model had multi-class classification F1 micro scores of 64%, 80% and 86% for thermal, light, and noise preference, respectively. The discussion outlines how these models can enhance comfort preference prediction when supplementing data from installed sensors. The approach presented prompts reflection on how the building analysis community evaluates, controls, and designs indoor environments through balancing the measurement of variables with occupant preferences in an intensive longitudinal way.
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Monitoring Transepidermal Water Loss and Skin Wettedness Factor with Battery-Free NFC Sensor. SENSORS 2020; 20:s20195549. [PMID: 32998315 PMCID: PMC7583755 DOI: 10.3390/s20195549] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 01/11/2023]
Abstract
The transepidermal water loss (TEWL) and the skin wettedness factor (SWF) are considered parts of a key perspective related to skincare. The former is used to determine the loss of water content from the stratum corneum (SC), while the latter is used to determine the human skin comfort level. Herein, we developed two novel approaches: (1) determination of the TEWL and the SWF based on a battery-free humidity sensor, and (2) the design of a battery-free smart skincare sensor device tag that can harvest energy from a near field communication (NFC)-enabled smartphone, making it a battery-free design approach. The designed skincare device tag has a diameter of 2.6 cm and could harvest energy (~3 V) from the NFC-enabled smartphone. A series of experimental tests involving the participation of eight and six subjects were conducted in vivo for the indoor and outdoor environments, respectively. During the experimental analysis, the skin moisture content level was measured at different times of the day using an android smartphone. The TEWL and SWF values were calculated based on these sensor readings. For the TEWL case: if the skin moisture is high, the TEWL is high, and if the skin moisture is low, the TEWL is low, ensuring that the skin moisture and the TEWL follow the same trend. Our smart skincare device is enclosed in a 3D flexible design print, and it is battery-free with an android application interface that is more convenient to carry outside than other commercially available battery-based devices.
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15
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Plant D, Leevers P. Injection moldable rate stiffening re‐entrant cell arrays for wearable impact protection. POLYM ENG SCI 2020. [DOI: 10.1002/pen.25400] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Daniel Plant
- Department of Mechanical EngineeringImperial College London London UK
| | - Patrick Leevers
- Department of Mechanical EngineeringImperial College London London UK
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Wang Z, He R, Chen K. Thermal comfort and virtual reality headsets. APPLIED ERGONOMICS 2020; 85:103066. [PMID: 32174354 DOI: 10.1016/j.apergo.2020.103066] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 06/10/2023]
Abstract
This study proposed to investigate the thermal properties and subjective thermal discomfort of five virtual reality headsets, and their relationships. Twenty-seven university students used each of the five headsets for 45 min. Microclimate temperature and relative humidity were measured by miniature dataloggers. Infrared thermography was used to measure temperature distribution on the contact points between user's face and the headsets. Participants reported subjective thermal discomfort associated with using each headset. The average microclimate temperature and relative humidity increased by 7.8 °C and 3.5% respectively after headset use. Overall subjective thermal discomfort increased along with duration of use and came primarily from the display. Applying the linear mixed-effects model showed that subjective thermal discomfort is positively correlated with duration of use, microclimate temperature, relative humidity and display coverage area. Conversely, thermal discomfort is negatively correlated with total coverage area, with microclimate temperature acting as the most significant contributing factor. The headsets were ranked by pairing the objective measurements with subjective evaluations.
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Affiliation(s)
- Zihao Wang
- School of Design, Hunan University, China.
| | - Renke He
- School of Design, Hunan University, China.
| | - Ke Chen
- School of Design, Hunan University, China.
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Vargas NT, Chapman CL, Ji W, Johnson BD, Gathercole R, Schlader ZJ. Increased skin wetness independently augments cool-seeking behaviour during passive heat stress. J Physiol 2020; 598:2775-2790. [PMID: 32347543 DOI: 10.1113/jp279537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/11/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS Skin wetness occurring secondary to the build-up of sweat on the skin provokes thermal discomfort, the precursor to engaging in cool-seeking behaviour. Associative evidence indicates that skin wetness stimulates cool-seeking behaviour to a greater extent than increases in core and mean skin temperatures. The independent contribution of skin wetness to cool-seeking behaviour during heat stress has never been established. We demonstrate that skin wetness augments cool-seeking behaviour during passive heat stress independently of differential increases in skin temperature and core temperature. We also identify that perceptions of skin wetness were not elevated despite increases in actual skin wetness. These data support the proposition that afferent signalling from skin wetness enhances the desire to engage in cool-seeking behaviour during passive heat stress. ABSTRACT This study tested the hypothesis that elevations in skin wetness augments cool-seeking behaviour during passive heat stress. Twelve subjects (6 females, age: 24 ± 2 y) donned a water-perfused suit circulating 34 °C water and completed two trials resting supine in a 28.5 ± 0.4 °C environment. The trials involved a 20 min baseline period (26 ± 3% relative humidity (RH)), 60 min while ambient humidity was maintained at 26±3% RH (LOW) or increased to 67 ± 5% RH (HIGH), followed by 60 min passive heat stress (HS) where the water temperature in the suit was incrementally increased to 50 °C. Subjects were able to seek cooling when their neck was thermally uncomfortable by pressing a button. Each button press initiated 30 s of -20 °C fluid perfusing through a custom-made device secured against the skin on the dorsal neck. Mean skin (Tskin ) and core (Tcore ) temperatures, mean skin wetness (Wskin ) and neck device temperature (Tdevice ) were measured continuously. Cool-seeking behaviour was determined from total time receiving cooling (TTcool ) and cumulative button presses. Tskin and Tcore increased during HS (P < 0.01) but were not different between conditions (P ≥ 0.11). Wskin was elevated in HIGH vs. LOW during HS (60 min: by + 0.06 ± 0.07 a.u., P ≤ 0.04). Tdevice was lower in HIGH vs. LOW at 40-50 min of HS (P ≤ 0.01). TTcool was greater for HIGH (330 ± 172 s) vs. LOW (225 ± 167 s, P < 0.01), while the number of cumulative button presses was greater from 40-60 min in HS for HIGH vs. LOW (P ≤ 0.04). Increased skin wetness amplifies the engagement in cool-seeking behaviour during passive heat stress.
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Affiliation(s)
- Nicole T Vargas
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA.,Thermal Ergonomics Laboratory, Discipline of Exercise and Sport Science, The University of Sydney, Sydney, NSW, Australia
| | - Christopher L Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Wenjie Ji
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | | | - Zachary J Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA.,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN, USA
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Nakamura D, Muraishi K, Hasegawa H, Yasumatsu M, Takahashi H. Effect of a cooling strategy combining forearm water immersion and a low dose of ice slurry ingestion on physiological response and subsequent exercise performance in the heat. J Therm Biol 2020; 89:102530. [DOI: 10.1016/j.jtherbio.2020.102530] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 10/25/2022]
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Effect of Weaving Structures on the Water Wicking-Evaporating Behavior of Woven Fabrics. Polymers (Basel) 2020; 12:polym12020422. [PMID: 32059351 PMCID: PMC7077655 DOI: 10.3390/polym12020422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/18/2020] [Accepted: 02/10/2020] [Indexed: 11/16/2022] Open
Abstract
Water transfer through porous textiles consists of two sequential processes: synchronous wicking–evaporating and evaporating alone. In this work we set out to identify the main structural parameters affecting the water transfer process of cotton fabrics. Eight woven fabrics with different floats were produced. The fabrics were evaluated on a specially designed instrument capable of measuring the water loss through a vertical wicking process. Each test took 120 min, and two phases were defined: Phase I for the first 10 min and Phase II for the last 110 min according to wicking behavior transition. Principal components and multivariate statistical methods were utilized to analyze the data collected. The results showed that Phase I dominated the whole wicking–evaporating process, and the moisture transfer speed in this phase varied with fabric structure, whereas the moisture transfer speeds in Phase II were similar and constant regardless of fabric structure. In addition, fabric with more floats has high water transfer speed in Phase I due to its loosened structure with more macropores.
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West AM, Tarrier J, Hodder S, Havenith G. Sweat distribution and perceived wetness across the human foot: the effect of shoes and exercise intensity. ERGONOMICS 2019; 62:1450-1461. [PMID: 31422758 DOI: 10.1080/00140139.2019.1657185] [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: 03/07/2019] [Accepted: 06/08/2019] [Indexed: 05/29/2023]
Abstract
This study investigates foot sweat distribution with and without shoes and the relationship between foot sweat distribution and perceived wetness to enhance guidance for footwear design. Fourteen females performed low-intensity running with nude feet and low- and high-intensity running with shoes (55%VO2max and 75%VO2max, respectively) on separate occasions. Right foot sweat rates were measured at 14 regions using absorbent material applied during the last 5 min of each work intensity. Perceptual responses were recorded for the body, foot and four foot regions. Foot sweat production was 22% greater nude (p < .001) and with shoes did not increase with exercise intensity (p = .14). Highest sweat rates were observed at the medial ankle and dorsal regions; lowest sweat rates at the toes. Perceptions of wetness and foot discomfort did not correspond with regions of high sweat production or low skin temperature but rather seemed dominated by tactile interactions caused by foot movement within the shoe. Practitioner summary: This study provides a detailed view of foot sweat distribution for female runners with and without shoes, providing important guidance for sock and footwear design. Importantly, perceptions of wetness and foot discomfort did not correspond with areas of high sweat production. Instead tactile interactions between the foot, sock/shoe play an important role. Abbreviations: VO2max: maximal oxygen consumption; HR: heart rate; RH: relative humidity; GSL: gross sweat loss; Nude-I1: without socks and shoes, low intensity running; Shod-I1: with socks and shoes, low intensity running; Shod-I2: with socks and shoes, high intensity running.
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Affiliation(s)
- Anna M West
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University , Loughborough , UK
| | - James Tarrier
- adidas FUTURE, adidas AG-World of Sports , Herzogenaurach , Germany
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University , Loughborough , UK
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University , Loughborough , UK
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Abstract
Humans perceive wetness on contact with a dry-cold material; however, the magnitude of wetness that can be perceived using dynamic touch remains unclear. This study assessed how the type of touch, namely hand movement (either statically or dynamically) and pressing force (either low or high pressure), affect the perception of wetness. The participants judged the magnitude of perceived wetness after four types of touch of four stimuli comprising four fabrics of varying water content and surface temperatures. Overall, the perceived wetness was differed between static and dynamic touch independent of pressure and the participants scored the dry-cold stimulus as relatively dry for dynamic touch. Furthermore, cluster analysis revealed individual differences in the recognition of wetness in dynamic touch conditions. These results revealed the variability in the mechanisms used by humans to perceive wetness. Additionally, we discussed the optimal methods to reproduce the wetness perception using this illusion.
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Watson C, Troynikov O, Lingard H. Design considerations for low-level risk personal protective clothing: a review. INDUSTRIAL HEALTH 2019; 57:306-325. [PMID: 30089764 PMCID: PMC6546585 DOI: 10.2486/indhealth.2018-0040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/30/2018] [Indexed: 05/04/2023]
Abstract
Personal protective clothing (PPC) is mandatory in hazardous industrial workplaces, but can increase thermophysiological strain, causing fatigue, reduced productivity, illness and injury. We systematically reviewed the literature on PPC and heat stress, focusing on research relating to working conditions of high temperature and humidity. PPC must protect industrial workers from a wide variety of hazards, including sun damage, abrasion, chemical spills and electrical burns; these competing demands inevitably compromise thermal performance. Fiber type, textile material construction and treatment need to be considered alongside garment fit and construction to design functional PPC providing wearers with adequate protection and comfort. Several approaches to materials and PPC testing-objective benchtop evaluation, mathematical modelling, and physiological testing-can be combined to provide high-quality thermal and vapor performance data. Our review provides a foundation and directions for further research in low-level risk PPC, where current research in fabrics and clothing in this category is very limited, and will help designers and manufacturers create industrial workwear with improved thermal management characteristics.
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Affiliation(s)
| | - Olga Troynikov
- Human Ecology and Clothing Science, RMIT University, Australia
| | - Helen Lingard
- Property, Construction and Project Management, RMIT University, Australia
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Valenza A, Bianco A, Filingeri D. Thermosensory mapping of skin wetness sensitivity across the body of young males and females at rest and following maximal incremental running. J Physiol 2019; 597:3315-3332. [DOI: 10.1113/jp277928] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/14/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- Alessandro Valenza
- THERMOSENSELABEnvironmental Ergonomics Research CentreLoughborough University Loughborough UK
- Sport and Exercise Sciences Research UnitSPPF DepartmentUniversity of Palermo Palermo Italy
| | - Antonino Bianco
- Sport and Exercise Sciences Research UnitSPPF DepartmentUniversity of Palermo Palermo Italy
| | - Davide Filingeri
- THERMOSENSELABEnvironmental Ergonomics Research CentreLoughborough University Loughborough UK
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VARGAS NICOLET, CHAPMAN CHRISTOPHERL, SACKETT JAMESR, JOHNSON BLAIRD, GATHERCOLE ROB, SCHLADER ZACHARYJ. Thermal Behavior Differs between Males and Females during Exercise and Recovery. Med Sci Sports Exerc 2019; 51:141-152. [DOI: 10.1249/mss.0000000000001756] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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A Review on Thermal Comfort Evaluation of Head-Worn Devices. ADVANCES IN ERGONOMICS IN DESIGN 2019. [DOI: 10.1007/978-3-319-94706-8_62] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Godsmark CN, Tipton MJ, Dennis MR, House JR. Moisture vapour permeable gloves extend thermal endurance and safe work time more than other similarly permeable chemical-biological ancillary protective items. ERGONOMICS 2018; 61:1635-1645. [PMID: 30044705 DOI: 10.1080/00140139.2018.1503726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 07/18/2018] [Indexed: 06/08/2023]
Abstract
Working in Chemical Biological (CB) protective equipment causes thermoregulatory strain by restricting evaporative cooling. We quantified which impermeable ancillary items [gloves(G), body armour liner(BAL), respirator(R) and overboots(OB)] imposed the greatest and the least thermoregulatory strain through restricting evaporative cooling. The study was a five-condition repeated-measures design with male volunteers (n = 13) who stepped intermittently with recovery periods in a desert-like environment (40.5 °C, 20% rh). Conditions varied in the ensemble worn, with a matched weight secured to the area when an item was not worn: CON(CB suit plus all items), NR(no R), NBAL(no BAL [170g liner]), NG(no G) and NOB(no OB). The greatest reduction in thermoregulatory strain compared with CON occurred in NG when the rise of rectal temperature was attenuated by 0.37 °C.hr-1 (p < .001), extending tolerance time by 21.3% (p < .05) and improving perceived thermal comfort. The least improvement occurred for NOB. It is recommended that the G permeability be examined further. Practitioner summary: Thermoregulatory strain was quantified when wearing impermeable protective equipment. The thermal burden of intermittent exercise in desert-like environments was best alleviated by removing gloves compared to removing a respirator, overboots or body armour liner. Reducing the evaporative resistance of materials used for such kit, particularly gloves, should be investigated.
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Affiliation(s)
- Christie N Godsmark
- a Extreme Environments Laboratory, Department of Sport and Exercise Science , University of Portsmouth , Portsmouth , United Kingdom
| | - Michael J Tipton
- a Extreme Environments Laboratory, Department of Sport and Exercise Science , University of Portsmouth , Portsmouth , United Kingdom
| | - Michael R Dennis
- b Defence Science and Technology Laboratory, Porton Down , Salisbury , United Kingdom
| | - James R House
- a Extreme Environments Laboratory, Department of Sport and Exercise Science , University of Portsmouth , Portsmouth , United Kingdom
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Vargas NT, Chapman CL, Johnson BD, Gathercole R, Schlader ZJ. Skin wettedness is an important contributor to thermal behavior during exercise and recovery. Am J Physiol Regul Integr Comp Physiol 2018; 315:R925-R933. [DOI: 10.1152/ajpregu.00178.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We tested the hypothesis that mean skin wettedness contributes to thermal behavior to a greater extent than core and mean skin temperatures. In a 27.0 ± 1.0°C environment, 16 young participants (8 females) cycled for 30 min at 281 ± 51 W·m2, followed by 120 min of seated recovery. Mean skin and core temperatures and mean skin wettedness were recorded continuously. Participants maintained a thermally comfortable neck temperature throughout the protocol using a custom-made device. Neck device temperature provided an index of thermal behavior. Linear regression was performed using individual minute data with mean skin wettedness and core and mean skin temperatures as independent variables and neck device temperature as the dependent variable. Standarized β-coefficients were used to determine relative contributions to thermal behavior. Mean skin temperature differed from preexercise (32.6 ± 0.5°C) to 10 min into exercise (32.3 ± 0.6°C, P < 0.01). Core temperature increased from 37.1 ± 0.3°C preexercise to 37.7 ± 0.4°C by end exercise ( P < 0.01) and remained elevated through 30 min of recovery (37.2 ± 0.3°C, P < 0.01). Mean skin wettedness increased from preexercise [0.14 ± 0.03 arbitrary units (AU)] to 20 min into exercise (0.43 ± 0.09 AU, P < 0.01) and remained elevated through 80 min of recovery (0.18 ± 0.06 AU, P ≤ 0.05). Neck device temperature decreased from 26.4 ± 1.6°C preexercise to 18.5 ± 8.7°C 10 min into exercise ( P = 0.03) and remained depressed through 20 min of recovery (14.4 ± 11.2°C, P < 0.01). Mean skin wettedness (52 ± 24%) provided a greater contribution to thermal behavior compared with core (22 ± 22%, P = 0.06) and mean skin (26 ± 16%, P = 0.04) temperatures. Skin wettedness is an important contributing factor to thermal behavior during exercise and recovery.
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Affiliation(s)
- Nicole T. Vargas
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Christopher L. Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Blair D. Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Rob Gathercole
- lululemon athletica inc., Vancouver, British Columbia, Canada
| | - Zachary J. Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
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Raccuglia M, Sales B, Heyde C, Havenith G, Hodder S. Clothing comfort during physical exercise - Determining the critical factors. APPLIED ERGONOMICS 2018; 73:33-41. [PMID: 30098640 DOI: 10.1016/j.apergo.2018.05.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/21/2018] [Accepted: 05/27/2018] [Indexed: 05/28/2023]
Abstract
Clothing comfort is determined by multiple material and design factors. Wetness at the skin-clothing interface mainly impacts wear comfort. The current study investigated the combined effect of fabric contact area, fabric absolute sweat content and fabric moisture saturation percentage on wetness and stickiness sensations, during exercise. Moreover, factors causing wear (dis)comfort during exercise were identified. Higher fabric saturation percentage induced greater stickiness sensation, despite lower fabric contact area and absolute sweat content (typically associated with lower stickiness). Wetness perception did not change between fabrics with different saturation percentages, contact areas and sweat contents. Therefore, fabric saturation percentage mainly affects stickiness sensation of wet fabrics, overruling the impact of fabric contact area and absolute sweat content. No overall model of wear discomfort across all data could be developed, however, models for different time points were produced, with texture and stickiness sensations being the best predictors of wear discomfort at baseline and during exercise, respectively. This suggests that the factors determining clothing (dis)comfort are dynamics and alter importance during exercise activity.
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Affiliation(s)
- Margherita Raccuglia
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Benjamin Sales
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | | | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK.
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Raccuglia M, Heyde C, Lloyd A, Ruiz D, Hodder S, Havenith G. Anchoring biases affect repeated scores of thermal, moisture, tactile and comfort sensations in transient conditions. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2018; 62:1945-1954. [PMID: 30083800 PMCID: PMC6182318 DOI: 10.1007/s00484-018-1595-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/13/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
In this study, we addressed potential biases which can occur when sensorial scores of temperature, wetness and discomfort are repeatedly reported, in transient exercise conditions. We pointed out that, when repeatedly reported, previous sensorial scores can be set by the participants as reference values and the subsequent score may be given based on the previous point of reference, the latter phenomenon leading to a bias which we defined as 'anchoring bias'. Indeed, the findings shown that subsequent sensorial scores are prone to anchoring biases and that the bias consisted in a systematically higher magnitude of sensation as compared to when reported a single time only. As such, the study allowed recognition, quantification and mitigation of the identified bias which can improve the methodological rigour of research studies involving assessments of sensorial data in transient conditions.
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Affiliation(s)
- Margherita Raccuglia
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
- Adidas FUTURE Sport Science, Herzogenaurach, Germany.
| | | | - Alex Lloyd
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - Daniel Ruiz
- Adidas FUTURE Sport Science, Herzogenaurach, Germany
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
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The motivation to behaviorally thermoregulate during passive heat exposure in humans is dependent on the magnitude of increases in skin temperature. Physiol Behav 2018; 194:545-551. [PMID: 30017641 DOI: 10.1016/j.physbeh.2018.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/19/2018] [Accepted: 07/10/2018] [Indexed: 12/21/2022]
Abstract
We tested the hypothesis that the motivation to behaviorally thermoregulate in humans is dependent on the magnitude of changes in mean skin temperature. Ten healthy subjects (22 ± 3 y, 5 females) underwent 60 min of seated rest in a 32±1 °C or 42±1 °C environment (20% relative humidity). Trials were completed in a counterbalanced order. The motivation to behaviorally thermoregulate was measured using an operant behavior task on a fixed ratio schedule, in which subjects received thermal reinforcement after clicking a button 100 times. The reinforcer was 30 s of cooling on the dorsal aspect of the neck. The motivation to behave was defined as the cumulative number of button clicks over time and behavioral thermoregulation was defined as the change in neck skin temperature. Mean skin temperature was higher throughout the 42 °C versus the 32 °C trial (at 60 min: 36.3±0.5 °C vs. 34.5±0.5 °C, P < .01) and core temperature became higher in this trial 40 min into heat exposure (at 60 min: 37.2±0.2 °C vs. 37.1±0.1 °C, P ≤ .04), but did not differ from pre- heat exposure (P = .81). Neck skin temperature was lower in the 42 °C compared to the 32 °C trial starting at 30 min (33.7±0.8 °C vs. 35.3±0.5°C, P < .01), which was maintained thereafter (P ≤ .04). Cumulative responding for thermal reinforcement was greater in the 42 °C trial compared to the 32 °C trial at 20 min (180±155 clicks vs. 0±0 clicks, P < .01), which persisted thereafter (P < .01). These data indicate that the motivation to behaviorally thermoregulate during passive heat exposure in humans is dependent on the magnitude of increases in skin temperature.
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Raccuglia M, Heyde C, Lloyd A, Hodder S, Havenith G. Spatial and temporal migration of sweat: from skin to clothing. Eur J Appl Physiol 2018; 118:2155-2169. [PMID: 30027521 PMCID: PMC6153606 DOI: 10.1007/s00421-018-3941-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/09/2018] [Indexed: 11/17/2022]
Abstract
Purpose Moisture accumulation in clothing affects human performance and productivity through its impact on thermal balance and various aspects of discomfort. Building on our laboratory’s work on mapping sweat production across the body, this study aimed to obtain detailed spatial and temporal maps showing how this sweat migrates into a single clothing layer (T-shirt) during physical exercise. Method Eight male participants performed running exercise in a warm environment. Garment sweat absorption was mapped over a total running time of 50 min, in 10 separated running trials of different durations (5 min increments). After running, the garment was dissected into 22 different parts and local sweat absorption (ABSlocal) was quantified by weighing each garment part before and after drying. From ABSlocal, garment total sweat absorption (ABStotal) was estimated. Results After 50 min, Tcore rose from 37 ± 0.2 to 38.6 ± 0.3 °C, HR increased from 69 ± 15 to 163 ± 12 bpm (p < 0.001), GSL was 586 ± 86 g m−2. Clear patterns of sweat absorption reduction from superior-to-inferior and from medial-to-lateral T-shirt zones were observed, with the mid back medial and the low front hem showing the highest, respectively. Conclusions Quantitative data on garment total and regional sweat absorption were obtained and considerable variation between different garment zones was identified. These data can support the development of sport and personal protective clothing with the end goal to prevent workers’ heat-related injuries as well as maximise human performance and productivity. Electronic supplementary material The online version of this article (10.1007/s00421-018-3941-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Margherita Raccuglia
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.,Adidas FUTURE Sport Science, Herzogenaurach, Germany
| | | | - Alex Lloyd
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
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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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Hunt AP. The maximum evaporative potential of constant wear immersion suits influences the risk of excessive heat strain for helicopter aircrew. PLoS One 2018; 13:e0196606. [PMID: 29723267 PMCID: PMC5933755 DOI: 10.1371/journal.pone.0196606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 04/16/2018] [Indexed: 11/18/2022] Open
Abstract
The heat exchange properties of aircrew clothing including a Constant Wear Immersion Suit (CWIS), and the environmental conditions in which heat strain would impair operational performance, were investigated. The maximum evaporative potential (im/clo) of six clothing ensembles (three with a flight suit (FLY) and three with a CWIS) of varying undergarment layers were measured with a heated sweating manikin. Biophysical modelling estimated the environmental conditions in which body core temperature would elevate above 38.0°C during routine flight. The im/clo was reduced with additional undergarment layers, and was more restricted in CWIS compared to FLY ensembles. A significant linear relationship (r2 = 0.98, P<0.001) was observed between im/clo and the highest wet-bulb globe temperature in which the flight scenario could be completed without body core temperature exceeding 38.0°C. These findings provide a valuable tool for clothing manufacturers and mission planners for the development and selection of CWIS's for aircrew.
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Affiliation(s)
- Andrew P. Hunt
- School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Australia
- Institute of Heath and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
- Physical Ergonomics Group, Land Human Systems, Land Division, Defence Science and Technology Group, Melbourne, Australia
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Vargas NT, Chapman CL, Sackett JR, Abdul-Rashed J, McBryde M, Johnson BD, Gathercole R, Schlader ZJ. Thermal behavior remains engaged following exercise despite autonomic thermoeffector withdrawal. Physiol Behav 2018; 188:94-102. [PMID: 29410068 DOI: 10.1016/j.physbeh.2018.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 11/30/2022]
Abstract
We tested the hypothesis that thermal behavior during the exercise recovery compensates for elevated core temperatures despite autonomic thermoeffector withdrawal. In a thermoneutral environment, 6 females and 6 males (22 ± 1 y) cycled for 60 min (225 ± 46 W metabolic heat production), followed by 60 min passive recovery. Mean skin and core temperatures, skin blood flow, and local sweat rate were measured continually. Subjects controlled the temperature of their dorsal neck to perceived thermal comfort using a custom-made neck device. Neck device temperature provided an index of thermal behavior. Mean body temperature, calculated as the average of mean skin and core temperatures, provided an index of the stimulus for thermal behavior. To isolate the independent effect of exercise on thermal behavior during recovery, data were analyzed post-exercise the exact minute mean body temperature recovered to pre-exercise levels within a subject. Mean body temperature returned to pre-exercise levels 28 ± 20 min into recovery (Pre: 33.5 ± 0.2, Post: 33.5 ± 0.2 °C, P = 0.20), at which point, mean skin temperature had recovered (Pre: 29.6 ± 0.4, Post: 29.5 ± 0.5 °C, P = 0.20) and core temperature (Pre: 37.3 ± 0.2, Post: 37.5 ± 0.3 °C, P = 0.01) remained elevated. Post-exercise, skin blood flow (Pre: 59 ± 78, Post: 26 ± 25 PU, P = 0.10) and local sweat rate (Pre: 0.05 ± 0.25, Post: 0.13 ± 0.14 mg/cm2 min-1, P = 0.09) returned to pre-exercise levels, while neck device temperature was depressed (Pre: 27.4 ± 1.1, Post: 21.6 ± 7.4 °C, P = 0.03). These findings suggest that thermal behavior compensates for autonomic thermoeffector withdrawal in the presence of elevated core temperatures post-exercise.
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Affiliation(s)
- Nicole T Vargas
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Christopher L Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - James R Sackett
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jabril Abdul-Rashed
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Muhamed McBryde
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | | | - Zachary J Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA.
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Kakitsuba N. Current knowledge on the effects of humidity on physiological and psychological responses. ACTA ACUST UNITED AC 2018. [DOI: 10.1618/jhes.20.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Peripheral and central determinants of skin wetness sensing in humans. HANDBOOK OF CLINICAL NEUROLOGY 2018; 156:83-102. [PMID: 30454611 DOI: 10.1016/b978-0-444-63912-7.00005-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Evolutionarily, our ability to sense skin wetness and humidity (i.e., hygroreception) could have developed as a way of helping to maintain thermal homeostasis, as much as it is the case for the role of temperature sensation and thermoreception. Humans are not provided with a specific skin hygroreceptor, and recent studies have indicated that skin wetness is likely to be centrally processed as a result of the multisensory integration of peripheral inputs from skin thermoreceptors and mechanoreceptors coding the biophysical interactions between skin and moisture. The existence of a specific hygrosensation strategy for human wetness perception has been proposed and the first neurophysiologic model of skin wetness sensing has been recently developed. However, while these recent findings have shed light on some of the peripheral and central neural mechanisms underlying wetness sensing, our understanding of how the brain processes the thermal and mechanical inputs that give rise to one of our "most worn" skin sensory experiences is still far from being conclusive. Understanding these neural mechanisms is clinically relevant in the context of those neurologic conditions that are accompanied by somatosensory abnormalities. The present chapter will present the current knowledge on the peripheral and central determinants of skin wetness sensing in humans.
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Abstract
The processes of thermoregulation are roughly divided into two categories: autonomic and behavioral. Behavioral thermoregulation alone does not have the capacity to regulate core temperature, as autonomic thermoregulation. However, behavioral thermoregulation is often utilized to maintain core temperature in a normal environment and is critical for surviving extreme environments. Thermal comfort, i.e., the hedonic component of thermal perception, is believed to be important for initiating and/or activating behavioral thermoregulation. However, the mechanisms involved are not fully understood. Thermal comfort is usually obtained when thermal stimuli to the skin restore core temperature to a regulated level. Conversely, thermal discomfort is produced when thermal stimuli result in deviations of core temperature away from a regulated level. Regional differences in the thermal sensitivity of the skin, hypohydration, and adaptation of the skin may affect thermal perception. Thermal comfort and discomfort seem to be determined by brain mechanisms, not by peripheral mechanisms such as thermal sensing by the skin. The insular and cingulate cortices may play a role in assessing thermal comfort and discomfort. In addition, brain sites involved in decision making may trigger behavioral responses to environmental changes.
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Affiliation(s)
- Kei Nagashima
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Saitama, Japan.
| | - Ken Tokizawa
- National Institute of Occupational Safety and Health, Tokyo, Japan
| | - Shuri Marui
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Saitama, Japan
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Schlader ZJ, Coleman GL, Sackett JR, Sarker S, Chapman CL, Hostler D, Johnson BD. Behavioral thermoregulation in older adults with cardiovascular co-morbidities. Temperature (Austin) 2017; 5:70-85. [PMID: 29687045 PMCID: PMC5902208 DOI: 10.1080/23328940.2017.1379585] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 09/01/2017] [Accepted: 09/06/2017] [Indexed: 12/21/2022] Open
Abstract
We tested the hypotheses that older adults with cardiovascular co-morbidities will demonstrate greater changes in body temperature and exaggerated changes in blood pressure before initiating thermal behavior. We studied twelve healthy younger adults (Younger, 25 ± 4 y) and six older adults ('At Risk', 67 ± 4 y) taking prescription medications for at least two of the following conditions: hypertension, type II diabetes, hypercholesterolemia. Subjects underwent a 90-min test in which they voluntarily moved between cool (18.1 ± 1.8°C, RH: 29 ± 5%) and warm (40.2 ± 0.3°C, RH: 20 ± 0%) rooms when they felt 'too cool' (C→W) or 'too warm' (W→C). Mean skin and intestinal temperatures and blood pressure were measured. Data were analyzed as a change from pretest baseline. Changes in mean skin temperature were not different between groups at C→W (Younger: +0.2 ± 0.8°C, 'At Risk': +0.7 ± 1.8°C, P = 0.51) or W→C (Younger: +2.7 ± 0.6°C, 'At Risk': +2.9 ± 1.9°C, P = 0.53). Changes in intestinal temperature were not different at C→W (Younger: 0.0 ± 0.1°C, 'At Risk': +0.1 ± 0.2, P = 0.11), but differed at W→C (-0.1 ± 0.2°C vs. +0.1 ± 0.3°C, P = 0.02). Systolic pressure at C→W increased (Younger: +10 ± 9 mmHg, 'At Risk': +24 ± 17 mmHg) and at W→C decreased (Younger: -4 ± 13 mmHg, 'At Risk': -23 ± 19 mmHg) to a greater extent in 'At Risk' (P ≤ 0.05). Differences were also apparent for diastolic pressure at C→W (Younger: -2 ± 4 mmHg, 'At Risk': +17 ± 23 mmHg, P < 0.01), but not at W→C (Younger Y: +4 ± 13 mmHg, 'At Risk': -1 ± 6 mmHg, P = 0.29). Despite little evidence for differential control of thermal behavior, the initiation of behavior in 'at risk' older adults is preceded by exaggerated blood pressure responses.
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Affiliation(s)
- Zachary J. Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Gregory L. Coleman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - James R. Sackett
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Suman Sarker
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Christopher L. Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - David Hostler
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Blair D. Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
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James CA, Hayes M, Willmott AGB, Gibson OR, Flouris AD, Schlader ZJ, Maxwell NS. Defining the determinants of endurance running performance in the heat. Temperature (Austin) 2017; 4:314-329. [PMID: 28944273 PMCID: PMC5605161 DOI: 10.1080/23328940.2017.1333189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/16/2017] [Accepted: 05/16/2017] [Indexed: 10/25/2022] Open
Abstract
In cool conditions, physiologic markers accurately predict endurance performance, but it is unclear whether thermal strain and perceived thermal strain modify the strength of these relationships. This study examined the relationships between traditional determinants of endurance performance and time to complete a 5-km time trial in the heat. Seventeen club runners completed graded exercise tests (GXT) in hot (GXTHOT; 32°C, 60% RH, 27.2°C WBGT) and cool conditions (GXTCOOL; 13°C, 50% RH, 9.3°C WBGT) to determine maximal oxygen uptake (V̇O2max), running economy (RE), velocity at V̇O2max (vV̇O2max), and running speeds corresponding to the lactate threshold (LT, 2 mmol.l-1) and lactate turnpoint (LTP, 4 mmol.l-1). Simultaneous multiple linear regression was used to predict 5 km time, using these determinants, indicating neither GXTHOT (R2 = 0.72) nor GXTCOOL (R2 = 0.86) predicted performance in the heat as strongly has previously been reported in cool conditions. vV̇O2max was the strongest individual predictor of performance, both when assessed in GXTHOT (r = -0.83) and GXTCOOL (r = -0.90). The GXTs revealed the following correlations for individual predictors in GXTHOT; V̇O2maxr = -0.7, RE r = 0.36, LT r = -0.77, LTP r = -0.78 and in GXTCOOL; V̇O2maxr = -0.67, RE r = 0.62, LT r = -0.79, LTP r = -0.8. These data indicate (i) GXTHOT does not predict 5 km running performance in the heat as strongly as a GXTCOOL, (ii) as in cool conditions, vV̇O2max may best predict running performance in the heat.
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Affiliation(s)
- Carl A. James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
- National Sports Institute of Malaysia (Institut Sukan Negara), Bukit Jalil Stadium, Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Ashley G. B. Willmott
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, UK
| | - Andreas D. Flouris
- FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece
| | - Zachary J. Schlader
- Centre for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
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Filingeri D, Ackerley R. The biology of skin wetness perception and its implications in manual function and for reproducing complex somatosensory signals in neuroprosthetics. J Neurophysiol 2017; 117:1761-1775. [PMID: 28123008 DOI: 10.1152/jn.00883.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 01/11/2023] Open
Abstract
Our perception of skin wetness is generated readily, yet humans have no known receptor (hygroreceptor) to signal this directly. It is easy to imagine the sensation of water running over our hands or the feel of rain on our skin. The synthetic sensation of wetness is thought to be produced from a combination of specific skin thermal and tactile inputs, registered through thermoreceptors and mechanoreceptors, respectively. The present review explores how thermal and tactile afference from the periphery can generate the percept of wetness centrally. We propose that the main signals include information about skin cooling, signaled primarily by thinly myelinated thermoreceptors, and rapid changes in touch, through fast-conducting, myelinated mechanoreceptors. Potential central sites for integration of these signals, and thus the perception of skin wetness, include the primary and secondary somatosensory cortices and the insula cortex. The interactions underlying these processes can also be modeled to aid in understanding and engineering the mechanisms. Furthermore, we discuss the role that sensing wetness could play in precision grip and the dexterous manipulation of objects. We expand on these lines of inquiry to the application of the knowledge in designing and creating skin sensory feedback in prosthetics. The addition of real-time, complex sensory signals would mark a significant advance in the use and incorporation of prosthetic body parts for amputees in everyday life.NEW & NOTEWORTHY Little is known about the underlying mechanisms that generate the perception of skin wetness. Humans have no specific hygroreceptor, and thus temperature and touch information combine to produce wetness sensations. The present review covers the potential mechanisms leading to the perception of wetness, both peripherally and centrally, along with their implications for manual function. These insights are relevant to inform the design of neuroengineering interfaces, such as sensory prostheses for amputees.
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Affiliation(s)
- Davide Filingeri
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, United Kingdom;
| | - Rochelle Ackerley
- Department of Physiology, University of Gothenburg, Göteborg, Sweden; and.,Laboratoire Neurosciences Intégratives et Adaptatives (UMR 7260), Aix Marseille Université-Centre National de la Recherche Scientifique, Marseille, France
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Dotti F, Ferri A, Moncalero M, Colonna M. Thermo-physiological comfort of soft-shell back protectors under controlled environmental conditions. APPLIED ERGONOMICS 2016; 56:144-152. [PMID: 27184322 DOI: 10.1016/j.apergo.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 03/23/2016] [Accepted: 04/02/2016] [Indexed: 06/05/2023]
Abstract
The aim of the study was to investigate thermo-physiological comfort of three back protectors identifying design features affecting heat loss and moisture management. Five volunteers tested the back protectors in a climatic chamber during an intermittent physical activity. Heart rate, average skin temperature, sweat production, microclimate temperature and humidity have been monitored during the test. The sources of heat losses have been identified using infrared thermography and the participants answered a questionnaire to express their subjective sensations associated with their thermo-physiological condition. The results have shown that locally torso skin temperature and microclimate depended on the type of back protector, whose design allowed different extent of perspiration and thermal insulation. Coupling physiological measurements with the questionnaire, it was found that overall comfort was dependent more on skin wetness than skin temperature: the participants preferred the back protector with the highest level of ventilation through the shell and the lowest level of microclimate humidity.
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Affiliation(s)
- Francesca Dotti
- DISAT, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy.
| | - Ada Ferri
- DISAT, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy.
| | - Matteo Moncalero
- DICAM, Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, 40131, Bologna, Italy.
| | - Martino Colonna
- DICAM, Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, 40131, Bologna, Italy.
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Schlader ZJ, Coleman GL, Sackett JR, Sarker S, Chapman CL, Johnson BD. Activation of autonomic thermoeffectors preceding the decision to behaviourally thermoregulate in resting humans. Exp Physiol 2016; 101:1218-1229. [PMID: 27401832 DOI: 10.1113/ep085837] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/07/2016] [Indexed: 01/15/2023]
Abstract
What is the central question of this study? Do increases in metabolic heat production and sweat rate precede the initiation of thermoregulatory behaviour in resting humans exposed to cool and warm environments? What is the main finding and its importance? Thermoregulatory behaviour at rest in cool and warm environments is preceded by changes in vasomotor tone in glabrous and non-glabrous skin, but not by acute increases in metabolic heat production or sweat rate. These findings suggest that sweating and shivering are not obligatory for thermal behaviour to be initiated in humans. We tested the hypothesis that acute increases in metabolic heat production and sweating precede the initiation of thermoregulatory behaviour in resting humans exposed to cool and warm environments. Twelve healthy young subjects passively moved between 17 and 40°C rooms when they felt 'too cool' (C→W) or 'too warm' (W→C). Skin and internal (intestinal) temperatures, metabolic heat production, local sweat rate (forearm and chest) and cutaneous vascular conductance (CVC; forearm and fingertip) were measured continually. Compared with pretest baseline (31.8 ± 0.3°C), skin temperature was higher at C→W (32.0 ± 0.7°C; P = 0.01) and W→C (34.5 ± 0.5°C; P < 0.01). Internal temperature did not differ (P = 0.12) between baseline (37.2 ± 0.3°C), C→W (37.2 ± 0.3°C) and W→C (37.0 ± 0.3°C). Metabolic heat production was not different from baseline (40 ± 9 W m-2 ) at C→W (39 ± 7 W m-2 ; P = 0.50). Forearm (0.06 ± 0.01 mg cm-2 min-1 ) and chest (0.04 ± 0.02 mg cm-2 min-1 ) sweat rate at W→C did not differ from baseline (forearm, 0.05 ± 0.02 mg cm-2 min-1 and chest, 0.04 ± 0.02 mg cm-2 min-1 ; P ≥ 0.23). Forearm CVC was not different from baseline (0.30 ± 0.21 perfusion units (PU) mmHg-1 ) at C→W (0.24 ± 0.11 PU mmHg-1 ; P = 0.17), but was higher at W→C (0.65 ± 0.33 PU mmHg-1 ; P < 0.01). Fingertip CVC was different from baseline (2.6 ± 2.0 PU mmHg-1 ) at C→W (0.70 ± 0.42 PU mmHg-1 ; P < 0.01) and W→C (4.49 ± 1.66 PU mmHg-1 ; P < 0.01). Thermoregulatory behaviour at rest in cool and warm environments is preceded by changes in vasomotor tone in glabrous and non-glabrous skin, but not by acute increases in metabolic heat production or sweat rate.
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Affiliation(s)
- Zachary J Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Gregory L Coleman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - James R Sackett
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Suman Sarker
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Christopher L Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
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Song W, Wang F. The hybrid personal cooling system (PCS) could effectively reduce the heat strain while exercising in a hot and moderate humid environment. ERGONOMICS 2016; 59:1009-1018. [PMID: 26457872 DOI: 10.1080/00140139.2015.1105305] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study aimed to examine the effectiveness of a hybrid personal cooling system (PCS) in mitigating body heat stain while exercising in a hot environment. Eight subjects underwent two trials: PCS and CON (i.e. no cooling). All trials were conducted at an air temperature of 36 ± 0.5 °C and RH = 59 ± 5%. The key findings demonstrated that the PCS could significantly reduce the core temperature, mean skin temperature, heart rate and physiological strain index during both exercise and recovery periods (p < 0.05). Subjective perceptions were also significantly alleviated in PCS at the end of the exercise and during the recovery (p < 0.05). Besides, the PCS could also bring remarkable benefits in lowering local skin temperatures and in improving perceptual sensations in both upper and lower body during both exercise and recovery periods (p < 0.05). It was thus concluded that the hybrid PCS is effective in mitigating body heat strain while exercising in a hot environment. Practitioner Summary: In hot and humid environments, body heat dissipation through sweating is greatly restricted. Our newly developed hybrid PCS could effectively alleviate heat strain while exercising in hot environments. The findings contribute to the body of knowledge in improving the health and well-being of sportsmen while exercising in hot environments.
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Affiliation(s)
- Wenfang Song
- a Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk , Soochow University , Suzhou , China
- b Department of Apparel Design and Engineering , Soochow University , Suzhou , China
| | - Faming Wang
- a Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk , Soochow University , Suzhou , China
- b Department of Apparel Design and Engineering , Soochow University , Suzhou , China
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Gillis DJ, Barwood MJ, Newton PS, House JR, Tipton MJ. The influence of a menthol and ethanol soaked garment on human temperature regulation and perception during exercise and rest in warm, humid conditions. J Therm Biol 2016; 58:99-105. [PMID: 27157339 DOI: 10.1016/j.jtherbio.2016.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/19/2016] [Accepted: 04/22/2016] [Indexed: 01/22/2023]
Abstract
UNLABELLED This study assessed whether donning a garment saturated with menthol and ethanol (M/E) can improve evaporative cooling and thermal perceptions versus water (W) or nothing (CON) during low intensity exercise and rest in warm, humid conditions often encountered in recreational/occupational settings. It was hypothesised there would be no difference in rectal (Tre) and skin (Tsk) temperature, infra-red thermal imagery of the chest/back, thermal comfort (TC) and rating of perceived exertion (RPE) between M/E, W and CON, but participants would feel cooler in M/E versus W or CON. METHODS Six volunteers (mean [SD] 22 [4] years, 72.4 [7.4] kg and 173.6 [3.7] cm) completed (separate days) three, 60-min tests in 30°C, 70%rh, in a balanced order. After 15-min of seated rest participants donned a dry (CON) or 80mL soaked (M/E, W) long sleeve shirt appropriate to their intervention. They then undertook 30-min of low intensity stepping at a rate of 12steps/min on a 22.5cm box, followed by 15-min of seated rest. Measurements included heart rate (HR), Tre, Tsk (chest/back/forearm), thermal imaging (back/chest), thermal sensation (TS), TC and RPE. Data were reported every fifth minute as they changed from baseline and the area under the curves were compared by condition using one-way repeated measures ANOVA, with an alpha level of 0.05. RESULTS Tre differed by condition, with the largest heat storage response observed in M/E (p<0.05). Skin temperature at the chest/back/forearm, and thermal imaging of the chest all differed by condition, with the greatest rate of heat loss observed in W and M/E respectively (p<0.01). Thermal sensation differed by condition, with the coolest sensations observed in M/E (p<0.001). No other differences were observed. CONCLUSIONS Both M/E and W enhanced evaporative cooling compared CON, but M/E causes cooler sensations and a heat storage response, both of which are likely mediated by menthol.
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Affiliation(s)
- D Jason Gillis
- Human Performance Laboratory, Department of Sport and Movement Science, Salem State University, Salem, MA 01970, USA.
| | - M J Barwood
- Dept. Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-Upon-Tyne, UK
| | - P S Newton
- Human Performance Research and Development, Canadian Forces Morale and Welfare Services, Ottawa, Ontario, Canada
| | - J R House
- Extreme Environments Laboratory, Department of Sport and Exercise Science, Portsmouth University, Portsmouth PO1 2ER, UK
| | - M J Tipton
- Extreme Environments Laboratory, Department of Sport and Exercise Science, Portsmouth University, Portsmouth PO1 2ER, UK
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Hunt AP, Billing DC, Patterson MJ, Caldwell JN. Heat strain during military training activities: The dilemma of balancing force protection and operational capability. Temperature (Austin) 2016; 3:307-317. [PMID: 27857960 PMCID: PMC4965006 DOI: 10.1080/23328940.2016.1156801] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 11/02/2022] Open
Abstract
Military activities in hot environments pose 2 competing demands: the requirement to perform realistic training to develop operational capability with the necessity to protect armed forces personnel against heat-related illness. To ascertain whether work duration limits for protection against heat-related illness restrict military activities, this study examined the heat strain and risks of heat-related illness when conducting a military activity above the prescribed work duration limits. Thirty-seven soldiers conducted a march (10 km; ∼5.5 km h-1) carrying 41.8 ± 3.6 kg of equipment in 23.1 ± 1.8°C wet-bulb globe temperature. Body core temperature was recorded throughout and upon completion, or withdrawal, participants rated their severity of heat-related symptoms. Twenty-three soldiers completed the march in 107 ± 6.4 min (Completers); 9 were symptomatic for heat exhaustion, withdrawing after 71.6 ± 10.1 min (Symptomatic); and five were removed for body core temperature above 39.0°C (Hyperthermic) after 58.4 ± 4.5 min. Body core temperature was significantly higher in the Hyperthermic (39.03 ± 0.26°C), than Symptomatic (38.34 ± 0.44°C; P = 0.007) and Completers (37.94 ± 0.37°C; P<0.001) after 50 min. Heat-related symptom severity was significantly higher among Symptomatic (28.4 ± 11.8) compared to Completers (15.0 ± 9.8, P = 0.006) and Hyperthermic (13.0 ± 9.6, P = 0.029). The force protection provided by work duration limits may be preventing the majority of personnel from conducting activities in hot environments, thereby constraining a commander's mandate to develop an optimised military force. The dissociation between heat-related symptoms and body core temperature elevation suggests that the physiological mechanisms underpinning exhaustion during exertional heat stress should be re-examined to determine the most appropriate physiological criteria for prescribing work duration limits.
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Affiliation(s)
- Andrew P Hunt
- Land Division, Defense Science and Technology Group, Department of Defence , Fishermans Bend, Australia
| | - Daniel C Billing
- Land Division, Defense Science and Technology Group, Department of Defence , Fishermans Bend, Australia
| | - Mark J Patterson
- Land Division, Defense Science and Technology Group, Department of Defence , Fishermans Bend, Australia
| | - Joanne N Caldwell
- Land Division, Defense Science and Technology Group, Department of Defence, Fishermans Bend, Australia; Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong, NSW, Australia
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Tang KPM, Kan CW, Fan JT. Psychophysical Measurement of Wet and Clingy Sensation of Fabrics by the Volar Forearm Test. J SENS STUD 2015. [DOI: 10.1111/joss.12161] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- K. P. M. Tang
- Institute of Textiles and Clothing, The Hong Kong Polytechnic University; Hung Hom Hong Kong
| | - C. W. Kan
- Institute of Textiles and Clothing, The Hong Kong Polytechnic University; Hung Hom Hong Kong
| | - J. T. Fan
- Institute of Textiles and Clothing, The Hong Kong Polytechnic University; Hung Hom Hong Kong
- College of Human Ecology, Cornell University; Ithaca NY 14853
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Flouris AD, Schlader ZJ. Human behavioral thermoregulation during exercise in the heat. Scand J Med Sci Sports 2015; 25 Suppl 1:52-64. [DOI: 10.1111/sms.12349] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2014] [Indexed: 01/14/2023]
Affiliation(s)
- A. D. Flouris
- FAME Laboratory; Department of Exercise Science; University of Thessaly; Trikala Greece
| | - Z. J. Schlader
- Institute for Exercise and Environmental Medicine; Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center; Dallas Texas USA
- Department of Exercise and Nutrition Sciences; University at Buffalo; Buffalo New York USA
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Tang KPM, Wu YS, Chau KH, Kan CW, Fan JT. Characterizing the transplanar and in-plane water transport of textiles with gravimetric and image analysis technique: Spontaneous Uptake Water Transport Tester. Sci Rep 2015; 5:9689. [PMID: 25875329 PMCID: PMC4397916 DOI: 10.1038/srep09689] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/16/2015] [Indexed: 11/30/2022] Open
Abstract
Water absorption and transport property of textiles is important since it affects wear comfort, efficiency of treatment and functionality of product. This paper introduces an accurate and reliable measurement tester, which is based on gravimetric and image analysis technique, for characterising the transplanar and in-plane wicking property of fabrics. The uniqueness of this instrument is that it is able to directly measure the water absorption amount in real-time, monitor the direction of water transport and estimate the amount of water left on skin when sweating. Throughout the experiment, water supply is continuous which simulates profuse sweating. Testing automation could even minimise variation caused by subjective manipulation, thus enhancing testing accuracy. This instrument is versatile in terms of the fabrics could be tested. A series of shirting fabrics made by different fabric structure and yarn were investigated and the results show that the proposed method has high sensitivity in differentiating fabrics with varying geometrical differences. Fabrics with known hydrophobicity were additionally tested to examine the sensitivity of the instrument. This instrument also demonstrates the flexibility to test on high performance moisture management fabrics and these fabrics were found to have excellent transplanar and in-plane wicking properties.
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Affiliation(s)
- K. P. M. Tang
- Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Y. S. Wu
- Department of Fiber Science and Apparel Design, College of Human Ecology, Cornell University, Ithaca, 14853, NY, United States
| | - K. H. Chau
- Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - C. W. Kan
- Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - J. T. Fan
- Institute of Textiles and Clothing, the Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Department of Fiber Science and Apparel Design, College of Human Ecology, Cornell University, Ithaca, 14853, NY, United States
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