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Del Ferraro S, Falcone T, Morabito M, Bonafede M, Marinaccio A, Gao C, Molinaro V. Mitigating heat effects in the workplace with a ventilation jacket: Simulations of the whole-body and local human thermophysiological response with a sweating thermal manikin in a warm-dry environment. J Therm Biol 2024; 119:103772. [PMID: 38145612 DOI: 10.1016/j.jtherbio.2023.103772] [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: 06/21/2023] [Revised: 11/20/2023] [Accepted: 12/01/2023] [Indexed: 12/27/2023]
Abstract
Climate change is increasingly affecting human well-being and will inevitably impact on occupational sectors in terms of costs, productivity, workers' health and injuries. Among the cooling garment developed to reduce heat strain, the ventilation jacket could be considered for possible use in workplaces, as it is wearable without limiting the user's mobility and autonomy. In this study, simulations with a sweating manikin are carried out to investigate the effects of a short-sleeved ventilation jacket on human thermophysiological responses in a warm-dry scenario. Simulations were performed in a climatic chamber (air temperature = 30.1 °C; air velocity = 0.29 m/s; relative humidity = 30.0 %), considering two constant levels of metabolic rate M (M1 = 2.4 MET; M2 = 3.2 MET), a sequence of these two (Work), and three levels of fan velocities (lf = 0; lf=2; lf=4). The results revealed a more evident impact on the mean skin temperature (Tsk) compared to the rectal temperature (Tre), with significant decreases (compared to fan-off) at all M levels, for Tsk from the beginning and for Tre from the 61st minute. Skin temperatures of the torso zones decreased significantly (compared to fan-off) at all M levels, and a greater drop was registered for the Back. The fans at the highest level (lf=4) were significantly effective in improving whole-body and local thermal sensations when compared to fan-off, at all M levels. At the intermediate level (lf=2), the statistical significance varied with thermal zone, M and time interval considered. The results of the simulations also showed that the Lower Torso needs to be monitored at M2 level, as the drop in skin temperature could lead to local overcooling and thermal discomfort. Simulations showed the potential effectiveness of the ventilation jacket, but human trials are needed to verify its cooling power in real working conditions.
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Affiliation(s)
- Simona Del Ferraro
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
| | - Tiziana Falcone
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
| | - Marco Morabito
- Institute of BioEconomy (IBE), National Research Council, Via Madonna Del Piano 10, 50019, Sesto Fiorentino, FI, Italy; Centre of Bioclimatology, University of Florence, Piazzale Delle Cascine 18, 50144, Florence, Italy.
| | - Michela Bonafede
- Laboratory of Occupational and Environmental Epidemiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Alessandro Marinaccio
- Laboratory of Occupational and Environmental Epidemiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Chuansi Gao
- Aerosol and Climate Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Sölvegatan 26, Lund, Sweden.
| | - Vincenzo Molinaro
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
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Donnan KJ, Williams EL, Bargh MJ. The effectiveness of heat preparation and alleviation strategies for cognitive performance: A systematic review. Temperature (Austin) 2023; 10:404-433. [PMID: 38130656 PMCID: PMC10732620 DOI: 10.1080/23328940.2022.2157645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022] Open
Abstract
A range of occupational and performance contexts (e.g. military personnel operations, emergency services, sport) require the critical maintenance of cognitive performance in environmentally challenging environments. Several reviews exist which evaluate the effectiveness of heat preparation strategies to facilitate physical performance. To date, no review has explored the usefulness of heat preparation strategies for cognitive performance. Therefore, this systematic review aimed to evaluate a range of interventions for the maintenance of cognitive performance, during or following active or passive heat exposure. Studies to be included were assessed by two authors reviewing title, abstract, and full-text. Forty articles were identified which met the inclusion criteria. Interventions were categorised into chronic (i.e. acclimation/acclimatisation) and acute strategies (i.e. hydration, cooling, supplementation, psychological). The results indicate that medium-term consecutive heat acclimation may mitigate some cognitive deficits under heat stress, although heat acclimation effectiveness could be influenced by age. Further, pre-cooling appears the most effective cooling method for maintaining cognitive performance under heat stress, although results were somewhat ambiguous. The hydration literature showed that the most effective hydration strategies were those which individualised electrolyte fortified fluid volumes to match for sweat loss. Limited research exploring psychological interventions indicates that motivational self-talk could be facilitative for maintaining cognitive skills following exercise in hot conditions. These findings can be used to help inform strategies for maintaining critical cognitive and decision-making skills in hot environments.
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Affiliation(s)
- Kate J. Donnan
- Department of Sport, Exercise, and Rehabilitation Sciences, University of Hull, Hull, HU6 7RX, UK
| | - Emily L. Williams
- Centre for Human Performance, Carnegie School of Sport, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - Melissa J. Bargh
- School of Sport and Exercise Science, College of Social Science of University of Lincoln, Lincoln, LN6 7TS, UK
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Yeoman K, Weakley A, DuBose W, Honn K, McMurry T, Eiter B, Baker B, Poplin G. Effects of heat strain on cognitive function among a sample of miners. APPLIED ERGONOMICS 2022; 102:103743. [PMID: 35313260 PMCID: PMC9170134 DOI: 10.1016/j.apergo.2022.103743] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 02/24/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Heat stress is associated with workplace injuries, likely through a combination of fatigue, reduced cognitive function, and thermal discomfort. The purpose of this study was to evaluate four cognitive tasks for sensitivity to heat stress. Eight participants performed treadmill exercise followed by assessments of serial reaction time (RT), Stroop effect, verbal delayed memory, and continuous performance working memory in an environmental chamber. A control (21.1 °C) trial, and "Hot 1" and "Hot 2" (both 37.8 °C) trials were run sequentially on two separate days to evaluate the four cognitive tasks. Heat strain (comparing Hot 1 and Hot 2 with the control trial) resulted in impairments in the serial RT test response and Stroop accuracy. Delayed memory was impacted only in the Hot 2 trial compared with the control trial. Given the demonstrated impact of heat on cognitive processes relevant to workers' real-world functioning in the workplace, understanding how to assess and monitor vigilant attention in the workplace is essential.
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Affiliation(s)
- Kristin Yeoman
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA.
| | - Alyssa Weakley
- University of California Davis School of Medicine, Department of Neurology, 4860 Y St #3900, Sacramento, CA, 95817, USA
| | - Weston DuBose
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
| | - Kimberly Honn
- Washington State University Sleep and Performance Research Center & Elson S. Floyd College of Medicine Washington State University, 412 E. Spokane Falls Blvd., Spokane, WA, USA
| | - Timothy McMurry
- University of Virginia Department of Public Health Sciences, PO Box 800717, Charlottesville, VA, 22908, USA
| | - Brianna Eiter
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
| | - Brent Baker
- National Institute for Occupational Safety and Health, 1095 Willowdale Road, MS 4020, Morgantown, WV, 26505-2888, USA
| | - Gerald Poplin
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
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The influence of rest break frequency and duration on physical performance and psychophysiological responses: a mining simulation study. Eur J Appl Physiol 2022; 122:2087-2097. [PMID: 35727402 PMCID: PMC9381606 DOI: 10.1007/s00421-022-04979-3] [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: 02/01/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022]
Abstract
Purpose To investigate the influence of shorter, more frequent rest breaks during simulated work (outdoor mining) in the heat on physical performance and psychophysiological responses. Methods On separate days, thirteen males undertook two 225 min simulation trials in the afternoon (12.00–3.45 pm) including 180 min of treadmill walking at a constant rate of perceived exertion of 11 (or ‘light’) on the 6–20 Borg scale in a heat chamber (37 °C, 40% RH), interspersed with 45 min of rest breaks in an air-conditioned room (22 °C, 35% RH). Rest breaks in the current practice (CP) trial occurred at 1.00 and 2.30 pm (30 min and 15 min, respectively), while in the experimental (EXP) trial were at 1.00 (15 min), 1.45, 2.25 and 3.05 pm (10 min each). Results Total distance covered was not different (p = 0.086) between CP (12,858 ± 2207 m) and EXP (12,094 ± 2174 m). Heart rate, thermal sensation and thermal comfort were significantly higher at 120–180 min (all p < 0.05) in CP compared to EXP. Moderate- to large-effect sizes (Hedge’s g) between trials were also found at 120–180 min for core temperature (g = 0.50 and 0.99, respectively). No differences were found between trials for cognitive performance, perceived fatigue, urine specific gravity, or total water intake (p > 0.05). Conclusion Shorter, more frequent rest breaks have little impact on physical performance, thermal strain and exercise-related sensations. Current practices should remain in place until further studies can be conducted on an actual mine site during summer where outdoor workers perform their work duties.
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Bonell A, Nadjm B, Samateh T, Badjie J, Perry-Thomas R, Forrest K, Prentice AM, Maxwell NS. Impact of Personal Cooling on Performance, Comfort and Heat Strain of Healthcare Workers in PPE, a Study From West Africa. Front Public Health 2021; 9:712481. [PMID: 34540787 PMCID: PMC8440920 DOI: 10.3389/fpubh.2021.712481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/10/2021] [Indexed: 01/25/2023] Open
Abstract
Background: Personal protective equipment (PPE) is an essential component of safely treating suspected or confirmed SARS-CoV-2 patients. PPE acts as a barrier to heat loss, therefore increasing the risk of thermal strain which may impact on cognitive function. Healthcare workers (HCWs) need to be able to prioritize and execute complex tasks effectively to ensure patient safety. This study evaluated pre-cooling and per-cooling methods on thermal strain, thermal comfort and cognitive function during simulated emergency management of an acutely unwell patient. Methods: This randomized controlled crossover trial was run at the Clinical Services Department of the Medical Research Unit The Gambia. Each participant attended two sessions (Cool and Control) in standard PPE. Cool involved pre-cooling with an ice slurry ingestion and per-cooling by wearing an ice-vest external to PPE. Results: Twelve participants completed both sessions. There was a significant increase in tympanic temperature in Control sessions at both 1 and 2 h in PPE (p = 0.01). No significant increase was seen during Cool. Effect estimate of Cool was -0.2°C (95% CI -0.43; 0.01, p = 0.06) post 1 h and -0.28°C (95% CI -0.57; 0.02, p = 0.06) post 2 h on tympanic temperature. Cool improved thermal comfort (p < 0.001), thermal sensation (p < 0.001), and thirst (p = 0.04). No difference on cognitive function was demonstrated using multilevel modeling. Discussion: Thermal strain in HCWs wearing PPE can be safely reduced using pre- and per-cooling methods external to PPE.
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Affiliation(s)
- Ana Bonell
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Behzad Nadjm
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Tida Samateh
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Jainaba Badjie
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Robyn Perry-Thomas
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Karen Forrest
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Andrew M. Prentice
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, United Kingdom
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Ciuha U, Valenčič T, Mekjavic IB. Cooling efficiency of vests with different cooling concepts over 8-hour trials. ERGONOMICS 2021; 64:625-639. [PMID: 33222661 DOI: 10.1080/00140139.2020.1853820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/16/2020] [Indexed: 06/11/2023]
Abstract
As frequency and severity of heat waves are increasing, personal cooling systems are being considered as a tool to mitigate heat strain in workers in various occupational settings. This study assessed cooling capacities (C; W·h·m-2) of various commercially available vests using different cooling concepts. Measurements were conducted over 8 h in a climatic chamber (Ta: 35 °C, RH: 35 %) using a thermal manikin (Ts: 35 °C). Cooling power (P) and duration of efficient cooling (tc) determined the C value of each vest. Among the cooling concepts the active cooling vests were the most efficient, extracting 331 W·h·m-2, followed by the vests with phase change material (PCM) inserts, hybrid and evaporative vests, extracting a maximum of 164 W·h·m-2, 146 W·h·m-2 and 113 W·h·m-2, respectively. While some vests with PCM inserts provided intense but shorter cooling, evaporative vests provided mild but longer cooling throughout. Practitioner summary: The study assessed the cooling capacity of commercially available vests, using a thermal manikin. The vests present an affordable solution in various occupational settings where air-conditioning is not an option. A range of cooling capacities among different cooling concepts and vests of the same category were noted. Abbreviations: ACVs: air-cooled vests; LCVs: liquid-cooled vests; ECVs: evaporative cooling vests; HCVs: hybrid cooling vests; PCVs: phase-change cooling vests; PCM: phase change material; C: cooling capacity; Rt: thermal resistance; Re: evaporative resistance; Re (%): relative evaporative resistance; P: cooling power; Pmax: maximal cooling power; Pavg: average cooling power; tc: cooling duration; AUC: area under the curve; Ta: ambient temperature; RH: relative humidity; va: chamber air flow; Ts: manikin surface temperature.
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Affiliation(s)
- Urša Ciuha
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Tamara Valenčič
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
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Taylor NAS, Lee JY, Kim S, Notley SR. Physiological interactions with personal-protective clothing, physically demanding work and global warming: An Asia-Pacific perspective. J Therm Biol 2021; 97:102858. [PMID: 33863427 DOI: 10.1016/j.jtherbio.2021.102858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 01/03/2023]
Abstract
The Asia-Pacific contains over half of the world's population, 21 countries have a Gross Domestic Product <25% of the world's largest economy, many countries have tropical climates and all suffer the impact of global warming. That 'perfect storm' exacerbates the risk of occupational heat illness, yet first responders must perform physically demanding work wearing personal-protective clothing and equipment. Unfortunately, the Eurocentric emphasis of past research has sometimes reduced its applicability to other ethnic groups. To redress that imbalance, relevant contemporary research has been reviewed, to which has been added information applicable to people of Asian, Melanesian and Polynesian ancestry. An epidemiological triad is used to identify the causal agents and host factors of work intolerance within hot-humid climates, commencing with the size dependency of resting metabolism and heat production accompanying load carriage, followed by a progression from the impact of single-layered clothing through to encapsulating ensembles. A morphological hypothesis is presented to account for inter-individual differences in heat production and heat loss, which seems to explain apparent ethnic- and gender-related differences in thermoregulation, at least within thermally compensable states. The mechanisms underlying work intolerance, cardiovascular insufficiency and heat illness are reviewed, along with epidemiological data from the Asia-Pacific. Finally, evidence-based preventative and treatment strategies are presented and updated concerning moisture-management fabrics and barriers, dehydration, pre- and post-exercise cooling, and heat adaptation. An extensive reference list is provided, with >25 recommendations enabling physiologists, occupational health specialists, policy makers, purchasing officers and manufacturers to rapidly extract interpretative outcomes pertinent to the Asia-Pacific.
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Affiliation(s)
- Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
| | - Joo-Young Lee
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea
| | - Siyeon Kim
- Human Convergence Technology R&D Department, Korea Institute of Industrial Technology, Ansan, Republic of Korea
| | - Sean R Notley
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
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Ashworth ET, Cotter JD, Kilding AE. Impact of elevated core temperature on cognition in hot environments within a military context. Eur J Appl Physiol 2021; 121:1061-1071. [PMID: 33426575 PMCID: PMC7797274 DOI: 10.1007/s00421-020-04591-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 12/17/2020] [Indexed: 01/31/2023]
Abstract
PURPOSE Cognition can be impaired during exercise in the heat, potentially contributing to military casualties. To our knowledge, the independent role of elevated core temperature during exercise has not been determined. The aim of the current study was to evaluate effects of elevated core temperature on cognition during physically encumbering, heated exercise, and to determine whether the perceptual cooling effects of menthol preserves cognition. METHODS Eight participants complete three trials in randomised order: one normothermic (CON) and two with elevated (38.5°C) core temperature, induced by prior immersion in neutral versus hot water The CON trial and one hot trial (HOT) used a water mouth-rinse following each cognitive task of the trial, (HOT) while the other used a menthol mouth-rinse (MENT). Participants walked in humid heat (33°C, 75% relative humidity) in military clothing, completing a cognitive battery of reaction time, perceptual processing, working memory, executive function, cognitive flexibility, vigilance, and declarative memory. RESULTS No differences in cognitive performance were observed between any conditions. Near-infrared spectroscopy showed greater oxygenated haemoglobin tissue content in HOT and MENT compared to CON (ΔO2Hb-deO2Hb: 2.3 ± 4.5 µM, p < .024), and lower deoxygenated haemoglobin in MENT than in CON or HOT (p = .017), suggesting higher brain metabolism during the more stressful conditions. CONCLUSION Moderately elevated core (38.5°C) and skin temperature does not appear to impair cognitive performance during exercise despite mildly elevated cerebral metabolism. The effects of menthol remain undetermined due to the lack of heat-mediated cognitive impairment.
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Affiliation(s)
- Edward Tom Ashworth
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, 17 Antares Place, Rosedale, Auckland, 0632, New Zealand.
| | - James David Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, 55/47 Union Street W, North Dunedin, Dunedin, 9016, New Zealand
| | - Andrew Edward Kilding
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, 17 Antares Place, Rosedale, Auckland, 0632, New Zealand
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Kajiki M, Yamashita N, Ito R, Matsumoto T. Effects of air-perfused rucksack on physiological and perceptual strain during low-intensity exercise in a hot environment. Temperature (Austin) 2020; 7:157-164. [PMID: 33015243 DOI: 10.1080/23328940.2020.1757991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The upcoming Tokyo Olympic and Paralympic Games may be held amid extremely high wet-bulb globe temperature conditions. Many studies have focused on countermeasures to prevent the reduction in exercise performance in the heat. However, cooling strategies for managing heat stress of staff and spectators remain poorly understood. The present study investigated the effects of a lightweight fan cooling device, namely a commercially available air-perfused rucksack, on physiological and perceptual responses during low-intensity exercise in a hot environment. Ten males walked (5.5 km/h, 2.0% gradient) for 60 min in hot conditions (35°C, 50% relative humidity). All participants performed two trials with and without the air-perfused rucksack, respectively. Air was blown onto the upper back and neck via two fans attached on either side of the rucksack. Rectal temperature, neck skin temperature, heart rate, and physiological strain index were significantly lower during walking (P < 0.05) with the rucksack. Additionally, the ratings of perceived exertion, thermal sensation, and thermal comfort were significantly lower (P < 0.05) with the rucksack. These data suggest that the air-perfused rucksack may be effective for managing heat stress of staff and spectators at the Tokyo Olympic and Paralympic Games. Abbreviations CON: control trial; ES: effect sizes; FAN: fan cooling trial; HR: heart rate; mTsk: mean skin temperature; pre: pre-exercise; PSI: physiological strain index; RPE: rating of perceived exertion; SD: standard deviation; TC: thermal comfort; Tneck: neck skin temperature; Tre: rectal temperature; TS: thermal sensation.
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Affiliation(s)
- Masanobu Kajiki
- Laboratory for Exercise Physiology and Biomechanics, Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Naoyuki Yamashita
- Faculty of Arts and Sciences, Kyoto Institute of Technology, Kyoto, Japan
| | - Ryo Ito
- School of Liberal Arts and Sciences, Daido University, Nagoya, Japan
| | - Takaaki Matsumoto
- Laboratory for Exercise Physiology and Biomechanics, Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
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Polanczyk A, Piechota-Polanczyk A, Dmochowska A, Majder-Lopatka M, Salamonowicz Z. Analysis of the Effectiveness of Decontamination Fluids on the Level of Biological Contamination of Firefighter Suits. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17082815. [PMID: 32325845 PMCID: PMC7215583 DOI: 10.3390/ijerph17082815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/10/2020] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
The scope of tasks of chemical and ecological rescue procedures includes prevention of terrorist attacks with biological weapons. After each action, firefighters are obliged to clean and disinfect their outfits to prevent the potential spreading of harmful microorganisms. This study aimed to analyze the effectiveness of decontamination fluids used to disinfect firefighter's suits. Two types of clothes were analyzed: special combat clothing (NOMEX), and the heavy gas-tight chemical type 1a suit. Swabbed places were cut out and sterilized mechanically using detergent and alcohol. Each time, smears were made on sterile glass, fixed in pure ethanol and stained using the Gram method. After this, the staining samples were air dried and photographed under a light microscope at magnification 1000×. Each smear was made in triplicate and the relative number of stained microorganisms was analyzed using ImageJ software. The results showed that detergent significantly decreased the number of pathogens in the chest area on the NOMEX suit and the type 1a-gas-tight clothing and was more effective than alcohol, especially in case of the NOMEX suit. In conclusion, the detergent was more efficient in decontaminating the NOMEX outfit than the heavy gas-tight clothing, whose surface was better cleaned by the alcohol.
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Affiliation(s)
- Andrzej Polanczyk
- The Main School of Fire Service, Slowackiego 52/54 Street, 01-629 Warsaw, Poland; (A.D.); (M.M.-L.); (Z.S.)
| | | | - Anna Dmochowska
- The Main School of Fire Service, Slowackiego 52/54 Street, 01-629 Warsaw, Poland; (A.D.); (M.M.-L.); (Z.S.)
| | - Malgorzata Majder-Lopatka
- The Main School of Fire Service, Slowackiego 52/54 Street, 01-629 Warsaw, Poland; (A.D.); (M.M.-L.); (Z.S.)
| | - Zdzislaw Salamonowicz
- The Main School of Fire Service, Slowackiego 52/54 Street, 01-629 Warsaw, Poland; (A.D.); (M.M.-L.); (Z.S.)
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Douzi W, Dupuy O, Theurot D, Smolander J, Dugué B. Per-Cooling (Using Cooling Systems during Physical Exercise) Enhances Physical and Cognitive Performances in Hot Environments. A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1031. [PMID: 32041228 PMCID: PMC7036802 DOI: 10.3390/ijerph17031031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/25/2020] [Accepted: 01/29/2020] [Indexed: 12/19/2022]
Abstract
There are many important sport events that are organized in environments with a very hot ambient temperature (Summer Olympics, FIFA World Cup, Tour de France, etc.) and in hot locations (e.g., Qatar). Additionally, in the context of global warming and heat wave periods, athletes are often subjected to hot ambient temperatures. It is known that exercising in the heat induces disturbances that may provoke premature fatigue and negatively affects overall performance in both endurance and high intensity exercises. Deterioration in several cognitive functions may also occur, and individuals may be at risk for heat illnesses. To train, perform, work and recover and in a safe and effective way, cooling strategies have been proposed and have been routinely applied before, during and after exercise. However, there is a limited understanding of the influences of per-cooling on performance, and it is the subject of the present review. This work examines the influences of per-cooling of different areas of the body on performance in terms of intense short-term exercises ("anaerobic" exercises), endurance exercises ("aerobic" exercises), and cognitive functioning and provides detailed strategies that can be applied when individuals train and/or perform in high ambient temperatures.
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Affiliation(s)
| | | | | | | | - Benoit Dugué
- University of Poitiers, Laboratoire Mobilité Vieillissement Exercice (MOVE)-EA6314, Faculty of Sport Sciences, 8 Allée Jean Monnet, 86000 Poitiers, France; (W.D.); (O.D.); (D.T.); (J.S.)
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TOKIZAWA K, SON SY, OKA T, YASUDA A. Effectiveness of a field-type liquid cooling vest for reducing heat strain while wearing protective clothing. INDUSTRIAL HEALTH 2020; 58:63-71. [PMID: 31406053 PMCID: PMC6997718 DOI: 10.2486/indhealth.2018-0182] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 06/25/2019] [Indexed: 05/27/2023]
Abstract
This study examined the effectiveness of a field-type liquid cooling vest (LCV) worn underneath an impermeable protective suit on heat strain during walking. Eight men walked for 60 min at a moderate speed (3.0 km/h) wearing the suit in a warm environment (33°C, 60% relative humidity) without (control, CON) or with the LCV. A smaller increase in rectal temperature was recorded in participants in the LCV than in the CON condition (37.6 ± 0.1°C vs. 37.9 ± 0.1°C, p<0.05). Walking while wearing the LCV reduced the level of physiological heat strain, as measured by the mean skin temperature (35.5 ± 0.1°C vs. 36.3 ± 0.1°C), chest sweat rate (13.5 ± 3.0 mg/cm2/h vs. 16.6 ± 3.8 mg/cm2/h), chest cutaneous vascular conductance (349 ± 88% vs. 463 ± 122%), body weight loss (0.72 ± 0.05% vs. 0.93 ± 0.06%), and heart rate (101 ± 6 beats/min vs. 111 ± 7 beats/min) (p<0.05, for all comparisons). These changes were accompanied by a decrease in thermal sensation and discomfort. These results suggest that a field-type LCV attenuates exertional heat strain while wearing impermeable protective clothing.
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Affiliation(s)
- Ken TOKIZAWA
- National Institute of Occupational Safety and Health,
Japan
| | - Su-Young SON
- National Institute of Occupational Safety and Health,
Japan
- Present address: Kyungpook National University, Korea
| | - Tatsuo OKA
- National Institute of Occupational Safety and Health,
Japan
| | - Akinori YASUDA
- National Institute of Occupational Safety and Health,
Japan
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Bach AJE, Maley MJ, Minett GM, Zietek SA, Stewart KL, Stewart IB. An Evaluation of Personal Cooling Systems for Reducing Thermal Strain Whilst Working in Chemical/Biological Protective Clothing. Front Physiol 2019; 10:424. [PMID: 31031643 PMCID: PMC6474400 DOI: 10.3389/fphys.2019.00424] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 03/27/2019] [Indexed: 11/13/2022] Open
Abstract
Objective The use of personal cooling systems to mitigate heat strain on first-responders achieves two potential performance benefits relative to the absence of such cooling: (1) the completion of a workload with less effort; and/or (2) the completion of a greater workload for the same effort. Currently, claims made by manufacturers regarding the capability of their products for use in conjunction with chemical/biological protective clothing remain largely unsubstantiated. The purpose of this investigation was to evaluate the means by which heat strain can be alleviated during uncompensable heat stress in chemical/biological clothing, using the ASTM F2300-10 methodology. Methods Eight healthy males completed five trials of continuous walking (4.5 km h-1; 35°C; 49% RH) for up to 120 min while wearing one of four cooling systems and/or a National Fire and Protection Association 1994 Class-3 chemical/biological ensemble. The four cooling methods (ice vest [IV], phase-change vest [PCM], water-perfused suit [WS], and combination ice slurry/ice vest [SLIV]) and no cooling (CON). Results We observed significant improvements in trial times for IV (18 ± 10 min), PCM (20 ± 10 min) and SLIV (22 ± 10 min), but no differences for WS (4 ± 7 min). Heart rate, rectal, mean skin, and body temperatures were significantly lower in all cooling conditions relative to control at various matched time points in the first 60 min of exercise. Thermal sensation, comfort and perceived exertion all had significant main effects for condition, and time, there were no differences in their respective interactions. Conclusion The IV, PCM, and SLIV produced lower heart rate, mean skin, rectal and mean body temperatures in addition to improved work times compared to control. The WS did not improve work times possibly as a result of the cooling capacity of the suit abating, and magnifying thermal insulation. Considering the added time and resources required to implement combination cooling in the form of ice slurry and ice vest (SLIV), there was no significant additive effect for perception, cardiovascular strain, rectal temperature and total trial time relative to the phase change vest or ice vest alone. This may be a product of a "ceiling" effect for work limit set to 120 min as part of ASTM F2300-10.
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Affiliation(s)
- Aaron J E Bach
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Matthew J Maley
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Geoffrey M Minett
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Stephanie A Zietek
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kelly L Stewart
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Ian B Stewart
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia
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14
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LUNDGREN-KOWNACKI K, DAHL M, GAO C, JAKOBSSON K, LINNINGE C, SONG D, KUKLANE K. Exploring how a traditional diluted yoghurt drink may mitigate heat strain during medium-intensity intermittent work: a multidisciplinary study of occupational heat strain. INDUSTRIAL HEALTH 2018; 56:106-121. [PMID: 29057769 PMCID: PMC5889929 DOI: 10.2486/indhealth.2017-0030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
It is common practice in India to consume the dairy drink buttermilk as a way of mitigating occupational heat strain. This paper explores the thermoregulatory and hydration benefits of drinking buttermilk but also the impacts of work in a hot environment on the gut microbiota, renal and cognitive function. Twelve healthy participants were subjected to a 3-h period of medium load physical intermittent work in a climatic chamber (34°C, 60% RH). The subjects were given water, buttermilk (700 ml) or no rehydration at random. Mean body temperatures when no rehydration was given were significantly higher (p≤0.001). When subjects drank water or buttermilk they had a lower sweat rate than with no rehydration (p≤0.05) and the perception of feeling hot, uncomfortable, thirsty and physically exerted was significantly reduced (p≤0.05). A hormonal stress response at the end of the exposure was seen when not drinking (p≤0.05). No differences in cognitive abilities and gut microbiota were found. The exposure lowered the renal blood flow suggesting an acute impact of short term heat exposure. It was also found that buttermilk has a protective effect on this impact. Our results demonstrated that keeping hydrated by water/buttermilk consumption mitigates heat strain in well-nourished subjects.
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Affiliation(s)
- Karin LUNDGREN-KOWNACKI
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Sweden
- *To whom correspondence should be addressed. E-mail:
| | - Mats DAHL
- Department of Psychology, Lund University, Sweden
| | - Chuansi GAO
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Sweden
| | - Kristina JAKOBSSON
- Department of Laboratory Medicine Lund, Unit of Occupational and Environmental Medicine, Lund University
- Department of Public Health and Community Medicine, Unit of Occupational and Environmental Medicine Sahlgrenska Academy, University of Gothenburg
| | - Caroline LINNINGE
- Department of Food Technology, Engineering and Nutrition, Lund University, Sweden
| | - Danping SONG
- Department of Food Technology, Engineering and Nutrition, Lund University, Sweden
| | - Kalev KUKLANE
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Sweden
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15
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MacRae BA, Annaheim S, Spengler CM, Rossi RM. Skin Temperature Measurement Using Contact Thermometry: A Systematic Review of Setup Variables and Their Effects on Measured Values. Front Physiol 2018. [PMID: 29441024 DOI: 10.3389/fphys.2018.00029, 10.3389/fpls.2018.00029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Skin temperature (Tskin) is commonly measured using Tskin sensors affixed directly to the skin surface, although the influence of setup variables on the measured outcome requires clarification. Objectives: The two distinct objectives of this systematic review were (1) to examine measurements from contact Tskin sensors considering equilibrium temperature and temperature disturbance, sensor attachments, pressure, environmental temperature, and sensor type, and (2) to characterise the contact Tskin sensors used, conditions of use, and subsequent reporting in studies investigating sports, exercise, and other physical activity. Data sources and study selection: For the measurement comparison objective, Ovid Medline and Scopus were used (1960 to July 2016) and studies comparing contact Tskin sensor measurements in vivo or using appropriate physical models were included. For the survey of use, Ovid Medline was used (2011 to July 2016) and studies using contact temperature sensors for the measurement of human Tskinin vivo during sport, exercise, and other physical activity were included. Study appraisal and synthesis methods: For measurement comparisons, assessments of risk of bias were made according to an adapted version of the Cochrane Collaboration's risk of bias tool. Comparisons of temperature measurements were expressed, where possible, as mean difference and 95% limits of agreement (LoA). Meta-analyses were not performed due to the lack of a common reference condition. For the survey of use, extracted information was summarised in text and tabular form. Results: For measurement comparisons, 21 studies were included. Results from these studies indicated minor (<0.5°C) to practically meaningful (>0.5°C) measurement bias within the subgroups of attachment type, applied pressure, environmental conditions, and sensor type. The 95% LoA were often within 1.0°C for in vivo studies and 0.5°C for physical models. For the survey of use, 172 studies were included. Details about Tskin sensor setup were often poorly reported and, from those reporting setup information, it was evident that setups widely varied in terms of type of sensors, attachments, and locations used. Conclusions: Setup variables and conditions of use can influence the measured temperature from contact Tskin sensors and thus key setup variables need to be appropriately considered and consistently reported.
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Affiliation(s)
- Braid A MacRae
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland.,Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Simon Annaheim
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
| | - Christina M Spengler
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - René M Rossi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
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16
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MacRae BA, Annaheim S, Spengler CM, Rossi RM. Skin Temperature Measurement Using Contact Thermometry: A Systematic Review of Setup Variables and Their Effects on Measured Values. Front Physiol 2018; 9:29. [PMID: 29441024 PMCID: PMC5797625 DOI: 10.3389/fphys.2018.00029] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/09/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Skin temperature (Tskin) is commonly measured using Tskin sensors affixed directly to the skin surface, although the influence of setup variables on the measured outcome requires clarification. Objectives: The two distinct objectives of this systematic review were (1) to examine measurements from contact Tskin sensors considering equilibrium temperature and temperature disturbance, sensor attachments, pressure, environmental temperature, and sensor type, and (2) to characterise the contact Tskin sensors used, conditions of use, and subsequent reporting in studies investigating sports, exercise, and other physical activity. Data sources and study selection: For the measurement comparison objective, Ovid Medline and Scopus were used (1960 to July 2016) and studies comparing contact Tskin sensor measurements in vivo or using appropriate physical models were included. For the survey of use, Ovid Medline was used (2011 to July 2016) and studies using contact temperature sensors for the measurement of human Tskinin vivo during sport, exercise, and other physical activity were included. Study appraisal and synthesis methods: For measurement comparisons, assessments of risk of bias were made according to an adapted version of the Cochrane Collaboration's risk of bias tool. Comparisons of temperature measurements were expressed, where possible, as mean difference and 95% limits of agreement (LoA). Meta-analyses were not performed due to the lack of a common reference condition. For the survey of use, extracted information was summarised in text and tabular form. Results: For measurement comparisons, 21 studies were included. Results from these studies indicated minor (<0.5°C) to practically meaningful (>0.5°C) measurement bias within the subgroups of attachment type, applied pressure, environmental conditions, and sensor type. The 95% LoA were often within 1.0°C for in vivo studies and 0.5°C for physical models. For the survey of use, 172 studies were included. Details about Tskin sensor setup were often poorly reported and, from those reporting setup information, it was evident that setups widely varied in terms of type of sensors, attachments, and locations used. Conclusions: Setup variables and conditions of use can influence the measured temperature from contact Tskin sensors and thus key setup variables need to be appropriately considered and consistently reported.
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Affiliation(s)
- Braid A. MacRae
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Simon Annaheim
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
| | - Christina M. Spengler
- Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - René M. Rossi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
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17
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An investigation of thermophysiological responses of human while using four personal cooling strategies during heatwaves. J Therm Biol 2017; 70:37-44. [DOI: 10.1016/j.jtherbio.2017.05.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 05/23/2017] [Accepted: 05/25/2017] [Indexed: 11/23/2022]
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18
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Roh HT, So WY, Cho SY, Suh SH. Effects of Fluid Ingestion on Brain-Derived Neurotrophic Factor and Cognition During Exercise in the Heat. J Hum Kinet 2017; 58:73-86. [PMID: 28828079 PMCID: PMC5548156 DOI: 10.1515/hukin-2017-0074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We investigated the effects of fluid ingestion during exercise in different environments on the serum brain-derived neurotrophic factor and cognition among athletes. Ten collegiate male athletes (soccer, n = 5; rugby, n = 5) were enrolled, and they completed running tests in the following four conditions (60 min each): 1) thermoneutral temperature at 18°C (group 18); 2) high ambient temperature at 32°C without fluid ingestion (group 32); 3) high ambient temperature at 32°C with water ingestion (group 32+W); and 4) high ambient temperature at 32°C with sports drink ingestion (group 32+S). Serum brain-derived neurotrophic factor levels significantly increased in group 18 immediately after exercise when compared with those at rest and were significantly higher than those in group 32 immediately and 60 min after exercise (p < 0.05). In the Stroop Color and Word Test, significantly increased Word, Color, and Color-Word scores were observed in group 18 immediately after exercise compared to those at rest (p < 0.05). However, the Color-Word score appeared to be significantly lower in group 32 immediately after exercise compared to the other groups (p < 0.05) and at 60 min post-exercise compared to group 18 (p < 0.05). We found that the exercise performed in a thermoneutral environment improved cognitive function, but the exercise performed in a hot environment did not. The differences according to the exercise environment would be largely affected by brain-derived neurotrophic factor, and fluid ingestion regardless of the type of drink (water or sports beverage) was assumed to have contributed to the improvement in cognitive function caused by exercising in a hot environment.
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Affiliation(s)
- Hee-Tae Roh
- Department of Physical Education, College of Arts and Physical Education, Dong-A University, Busan, Republic of Korea
| | - Wi-Young So
- Sports and Health Care Major,College of Humanities and Arts, Korea, National University of Transportation, Chungju-si, Republic of Korea
| | - Su-Youn Cho
- Department of Physical Education, Yonsei University, Seoul, Republic of Korea
| | - Sang-Hoon Suh
- Department of Physical Education, Yonsei University, Seoul, Republic of Korea
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19
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Mekjavic IB, Ciuha U, Grönkvist M, Eiken O. The Effect of Low Ambient Relative Humidity on Physical Performance and Perceptual Responses during Load Carriage. Front Physiol 2017; 8:451. [PMID: 28729839 PMCID: PMC5498462 DOI: 10.3389/fphys.2017.00451] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 06/14/2017] [Indexed: 11/13/2022] Open
Abstract
Introduction: The study evaluated the effect of low ambient relative humidity on physical performance and perceptual responses during load carriage in a hot environment. Methods: Ten heat-unacclimatized male subjects participated in three 130-min trials, during which they walked on a treadmill, carrying a load of ~35 kg, at a speed of 3.2 km.h−1, with an incident wind at the same velocity and ambient temperature at 45°C. Each trial commenced with a 10-min baseline at 20°C and 50% relative humidity (RH), the subjects transferred to a climatic chamber and commenced their simulated hike, comprising two 50-min walks separated by a 20-min rest period. In two, full protective equipment (FP) trials, RH was 10% (partial pressure of water vapor, pH2O = 7.2 mmHg) in one (FP10), and 20% (pH2O = 14.4 mmHg; FP20) in the other. In the control trial, subjects were semi-nude (SN) and carried the equipment in their backpacks; RH was 20%. Measurements included oxygen uptake, ventilation, heart rate, rectal and skin temperatures, heat flux, temperature perception, and thermal comfort. Results: In FP20, four subjects terminated the trial prematurely due to signs of heat exhaustion; there were no such signs in FP10 or SN. Upon completion of the trials, pulmonary ventilation, heart rate, and rectal temperature were lower in FP10 (33 ± 5 l/min; 128 ± 21 bpm; 38.2 ± 0.4°C) and SN (34 ± 4 l/min; 113 ± 18 bpm; 38.1 ± 0.4°C than in FP20 (39 ± 8 l/min; 145 ± 12 bpm; 38.6 ± 0.4°C). Evaporation was significantly greater in the SN compared to FP10 and FP20 trials. FP10 was rated thermally more comfortable than FP20. Conclusion: A lower ambient partial pressure of water vapor, reflected in a lower ambient relative humidity, improved cardiorespiratory, thermoregulatory, and perceptual responses during load carriage.
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Affiliation(s)
- Igor B Mekjavic
- Environmental Physiology Laboratory, Department of Automation, Biocybernetics and Robotics, Jožef Stefan InstituteLjubljana, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser UniversityBurnaby, BC, Canada
| | - Ursa Ciuha
- Environmental Physiology Laboratory, Department of Automation, Biocybernetics and Robotics, Jožef Stefan InstituteLjubljana, Slovenia
| | - Mikael Grönkvist
- Department of Environmental Physiology, School of Health and Technology, Royal Institute of TechnologyStockholm, Sweden
| | - Ola Eiken
- Department of Environmental Physiology, School of Health and Technology, Royal Institute of TechnologyStockholm, Sweden
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20
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van den Heuvel AMJ, Haberley BJ, Hoyle DJR, Taylor NAS, Croft RJ. The independent influences of heat strain and dehydration upon cognition. Eur J Appl Physiol 2017; 117:1025-1037. [DOI: 10.1007/s00421-017-3592-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/18/2017] [Indexed: 01/08/2023]
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21
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Schlader ZJ, Temple JL, Hostler D. Exercise in personal protective equipment in a hot, humid environment does not affect risk propensity. Temperature (Austin) 2016; 3:262-270. [PMID: 27857956 PMCID: PMC4964995 DOI: 10.1080/23328940.2016.1148526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 10/26/2022] Open
Abstract
We tested the hypothesis that heat stress created by light exertion in encapsulating personal protective equipment (PPE) in a hot, humid environment increases risk propensity. Ten healthy subjects (29 ± 7 y) completed 2 trials presented in a counter-balanced manner. Subjects donned encapsulating PPE, and in one trial they wore a tube-lined shirt underneath that was perfused with 5°C water. Subjects completed 2 15 min bouts of walking exercise on a treadmill at ˜50% maximal heart rate in a 32°C, 81% RH environment. Subjects completed the Balloon Analog Risk Task (BART), an objective measure of risk-taking, before, between the 2 exercise bouts, and following the final exercise bout. Personal cooling lowered (P < 0.01) mean skin temperature by 8.0 ± 1.6°C. Intestinal temperature rose (P < 0.01) in both trials, but was lower (P < 0.01) at the end of exercise in the cooling trial (38.0 ± 0.3°C vs. 37.6 ± 0.3°C). BART derived indices of risk propensity were not affected by trial or time (trial × time interaction: P ≥ 0.33). These data indicate that 60 min of exposure to mild heat stress created by light exertion in encapsulating PPE does not affect risk-taking behavior.
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Affiliation(s)
- Zachary J Schlader
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
| | - Jennifer L Temple
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
| | - David Hostler
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
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Haran FJ, Dretsch MN, Bleiberg J. Performance on the Defense Automated Neurobehavioral Assessment across controlled environmental conditions. APPLIED NEUROPSYCHOLOGY-ADULT 2016; 23:411-7. [PMID: 27182844 DOI: 10.1080/23279095.2016.1166111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Neurocognitive assessment tools (NCAT) are commonly used to screen for changes in cognitive functioning following a mild traumatic brain injury and to assist with a return to duty decision. As such, it is critical to determine if performance on the Defense Automated Neurobehavioral Assessment (DANA) is adversely affected by operationally-relevant field environments. Differences in DANA performance between a thermoneutral environment and three simulated operationally-relevant field environments across the thermal stress continuum were calculated for 16 healthy U.S. Navy service members. Practice effects associated with brief test-retest intervals were calculated within each environmental condition. There were no significant differences between the simulated environmental conditions suggesting that performance on the DANA Brief is not impacted by thermal stress. Additionally, there were no significant differences in performance within each simulated environmental condition associated with repeated administrations.
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Affiliation(s)
- F Jay Haran
- a Naval Submarine Medical Research Laboratory (NSMRL) , Groton , CT , USA
| | - Michael N Dretsch
- b Warfighter Health Division, U.S. Army Aeromedical Research Laboratory , Fort Rucker , AL , USA
| | - Joseph Bleiberg
- c Walter Reed National Military Medical Center (WRNMMC) , Bethesda , MD , USA
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23
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de Rome L, Taylor EA, Croft RJ, Brown J, Fitzharris M, Taylor NAS. Thermal and cardiovascular strain imposed by motorcycle protective clothing under Australian summer conditions. ERGONOMICS 2016; 59:504-513. [PMID: 26280297 DOI: 10.1080/00140139.2015.1082632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Motorcycle protective clothing can be uncomfortably hot during summer, and this experiment was designed to evaluate the physiological significance of that burden. Twelve males participated in four, 90-min trials (cycling 30 W) across three environments (25, 30, 35 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p < 0.05). The thresholds for moderate (>38.5 °C) and profound hyperthermia (>40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °C. These outcomes demonstrate a need to enhance the heat dissipation capabilities of motorcycle clothing designed for summer use in hot climates, but without compromising impact protection. Practitioner's Summary: Motorcycle protective clothing can be uncomfortably hot during summer. This experiment was designed to evaluate the physiological significance of this burden across climatic states. In the heat, moderate (>38.5 °C) and profound hyperthermia (>40.0 °C) were predicted to occur within 105 and 180 min, respectively.
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Affiliation(s)
- Liz de Rome
- a Neuroscience Research Australia , Sydney , Australia
| | - Elizabeth A Taylor
- b Centre for Human and Applied Physiology, School of Medicine , University of Wollongong , Wollongong , Australia
| | - Rodney J Croft
- c School of Psychology , University of Wollongong , Wollongong , Australia
| | - Julie Brown
- a Neuroscience Research Australia , Sydney , Australia
| | - Michael Fitzharris
- d Monash Injury Research Institute and Monash University Accident Research Centre , Monash University , Melbourne , Australia
| | - Nigel A S Taylor
- b Centre for Human and Applied Physiology, School of Medicine , University of Wollongong , Wollongong , Australia
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Houssein M, Lopes P, Fagnoni B, Ahmaidi S, Yonis SM, Leprêtre PM. Hydration: The New FIFA World Cup's Challenge for Referee Decision Making? J Athl Train 2016; 51:264-6. [PMID: 26881750 DOI: 10.4085/1062-6050-51.3.04] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Various continental sporting events have exposed team sports referees to different environmental conditions. Several studies have focused on strategies to prevent athlete performance impairment induced by heat or warm (or both) conditions, but few authors have investigated the effect of heat on referees' performance. In a thermoneutral environment, referees' physical activity induced mild 2.0% dehydration, which was responsible for reductions in physical, psychomotor, and cognitive performances. Therefore, the hydration status of referees should be taken into account to reduce referees' errors and misjudgments in the heat.
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Affiliation(s)
- Mohamed Houssein
- Laboratoire de Recherche Adaptations Physiologiques à l'Exercice et Réadaptation à l'Effort, Université de Picardie Jules Verne, Amiens, France;,Université de Djibouti, Djibouti City
| | | | - Bruno Fagnoni
- Laboratoire de Recherche Adaptations Physiologiques à l'Exercice et Réadaptation à l'Effort, Université de Picardie Jules Verne, Amiens, France
| | - Said Ahmaidi
- Laboratoire de Recherche Adaptations Physiologiques à l'Exercice et Réadaptation à l'Effort, Université de Picardie Jules Verne, Amiens, France
| | | | - Pierre-Marie Leprêtre
- Laboratoire de Recherche Adaptations Physiologiques à l'Exercice et Réadaptation à l'Effort, Université de Picardie Jules Verne, Amiens, France
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Grélot L, Koulibaly F, Maugey N, Janvier F, Foissaud V, Aletti M, Savini H, Cotte J, Dampierre H, Granier H, Carmoi T, Sagui E. Moderate Thermal Strain in Healthcare Workers Wearing Personal Protective Equipment During Treatment and Care Activities in the Context of the 2014 Ebola Virus Disease Outbreak. J Infect Dis 2015; 213:1462-5. [PMID: 26655297 DOI: 10.1093/infdis/jiv585] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/27/2015] [Indexed: 11/14/2022] Open
Abstract
The extent of thermal strain while wearing personal protective equipment (PPE) during care activities for Ebola virus disease patients has not yet been characterized. From January to March 2015, 25 French healthcare workers (HCWs) in Conakry, Guinea, volunteered to be monitored while wearing PPE using an ingestible thermal sensor. The mean (standard deviation) working ambient temperature and relative humidity were 29.6 °C (2.0 °C) and 65.4% (10.3%), respectively; the mean time wearing PPE was 65.7 (13.5) minutes; and the mean core body temperature increased by 0.46 °C (0.20 °C). Four HCWs reached or exceeded a mean core body temperature of ≥ 38.5 °C. HCWs wearing PPE for approximately 1 hour exhibited moderate but safe thermal strain.
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Affiliation(s)
| | | | | | - Frédéric Janvier
- French Military Teaching Hospital Saint Anne, Biological Department, Toulon
| | - Vincent Foissaud
- French Military Teaching Hospital Percy, Internal Medicine Department, Clamart
| | - Marc Aletti
- French Military Teaching Hospital Percy, Internal Medicine Department, Clamart
| | - Hélène Savini
- French Military Teaching Hospital Laveran, Neurological Department, Marseille
| | - Jean Cotte
- French Military Teaching Hospital Saint Anne, Biological Department, Toulon
| | - Henry Dampierre
- French Forces Health Services, Fort Neuf de Vincennes, Cours des Maréchaux
| | - Hervé Granier
- French Military Teaching Hospital Clermont Tonnerre, Internal Medicine Department, Brest
| | - Thierry Carmoi
- French Military Teaching Hospital Val de Grâce, Internal Medicine Department Val de Grâce Military Academy, Paris, France
| | - Emmanuel Sagui
- Aix-Marseille University, Marseille French Military Teaching Hospital Laveran, Neurological Department, Marseille Val de Grâce Military Academy, Paris, France
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Larsen B, Snow R, Williams-Bell M, Aisbett B. Simulated Firefighting Task Performance and Physiology Under Very Hot Conditions. Front Physiol 2015; 6:322. [PMID: 26617527 PMCID: PMC4637425 DOI: 10.3389/fphys.2015.00322] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 10/23/2015] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To assess the impact of very hot (45°C) conditions on the performance of, and physiological responses to, a simulated firefighting manual-handling task compared to the same work in a temperate environment (18°C). METHODS Ten male volunteer firefighters performed a 3-h protocol in both 18°C (CON) and 45°C (VH). Participants intermittently performed 12 × 1-min bouts of raking, 6 × 8-min bouts of low-intensity stepping, and 6 × 20-min rest periods. The area cleared during the raking task determined work performance. Core temperature, skin temperature, and heart rate were measured continuously. Participants also periodically rated their perceived exertion (RPE) and thermal sensation. Firefighters consumed water ad libitum. Urine specific gravity (USG) and changes in body mass determined hydration status. RESULTS Firefighters raked 19% less debris during the VH condition. Core and skin temperature were 0.99 ± 0.20 and 5.45 ± 0.53°C higher, respectively, during the VH trial, and heart rate was 14-36 beats.min(-1) higher in the VH trial. Firefighters consumed 2950 ± 1034 mL of water in the VH condition, compared to 1290 ± 525 in the CON trial. Sweat losses were higher in the VH (1886 ± 474 mL) compared to the CON trial (462 ± 392 mL), though both groups were hydrated upon protocol completion (USG < 1.020). Participants' average RPE was higher in the VH (15.6 ± 0.9) compared to the CON trial (12.6 ± 0.9). Similarly, the firefighers' thermal sensation scores were significantly higher in the VH (6.4 ± 0.5) compared to the CON trial (4.4 ± 0.4). CONCLUSIONS Despite the decreased work output and aggressive fluid replacement observed in the VH trial, firefighters' experienced increases in thermal stress, and exertion. Fire agencies should prioritize the health and safety of fire personnel in very hot temperatures, and consider the impact of reduced productivity on fire suppression efforts.
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Affiliation(s)
- Brianna Larsen
- School of Exercise and Nutrition Sciences, Faculty of Health, Deakin UniversityMelbourne, VIC, Australia
| | - Rod Snow
- School of Exercise and Nutrition Sciences, Faculty of Health, Deakin UniversityMelbourne, VIC, Australia
- Centre for Physical Activity and Nutrition Research, Faculty of Health, Deakin UniversityMelbourne, VIC, Australia
| | - Michael Williams-Bell
- Faculty of Health Sciences, University of Ontario Institute of TechnologyOshawa, ON, Canada
| | - Brad Aisbett
- School of Exercise and Nutrition Sciences, Faculty of Health, Deakin UniversityMelbourne, VIC, Australia
- Centre for Physical Activity and Nutrition Research, Faculty of Health, Deakin UniversityMelbourne, VIC, Australia
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Ciuha U, Grönkvist M, Mekjavic IB, Eiken O. Strategies for increasing evaporative cooling during simulated desert patrol mission. ERGONOMICS 2015; 59:298-309. [PMID: 26094700 DOI: 10.1080/00140139.2015.1061142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 06/05/2015] [Indexed: 06/04/2023]
Abstract
UNLABELLED The study evaluated the efficiency of two heat dissipation strategies under simulated desert patrol missions. Ten men participated in four trials, during which they walked on a treadmill (45 °C, 20% relative humidity), carrying a load of 35 kg; two 50-min walks were separated by a 20-min rest. Cooling strategies, provided by an ambient air-ventilated vest (active cooling condition, AC), or water spraying of the skin during the rest (passive cooling condition, PC), in addition to reduced clothing and open zippers, were compared to conditions with full protective (FP) clothing and naked condition (NC). Skin temperature was higher during NC (37.9 ± 0.4 °C; p < 0.001), and rectal temperature and heart rate were higher during FP (38.6 ± 0.4 °C, p < 0.001 and 145 ± 12, p < 0.001, respectively), compared to other conditions. Four subjects terminated the trial prematurely due to signs of heat exhaustion in FP. Both cooling strategies substantially improved evaporative cooling. PRACTITIONER SUMMARY Cooling strategies, provided by an ambient air-ventilated vest and water spraying of the skin, were compared to conditions with full protective clothing and a naked condition during a simulated desert patrol mission. Both cooling strategies improved evaporative cooling and reduced heat strain, compared to the full protection condition.
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Affiliation(s)
- Ursa Ciuha
- a Jozef Stefan International Postgraduate School , Ljubljana , Slovenia
- b Biomed d.o.o., Research and Professional Consulting , Ljubljana , Slovenia
| | - Mikael Grönkvist
- c Department of Environmental Physiology , School of Health and Technology, Royal Institute of Technology , Stockholm , Sweden
| | - Igor B Mekjavic
- d Department of Automation, Biocybernetics and Robotics , Jozef Stefan Institute , Ljubljana , Slovenia
| | - Ola Eiken
- c Department of Environmental Physiology , School of Health and Technology, Royal Institute of Technology , Stockholm , Sweden
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Ando S, Komiyama T, Sudo M, Kiyonaga A, Tanaka H, Higaki Y. The effects of temporal neck cooling on cognitive function during strenuous exercise in a hot environment: a pilot study. BMC Res Notes 2015; 8:202. [PMID: 26025443 PMCID: PMC4467620 DOI: 10.1186/s13104-015-1210-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 05/22/2015] [Indexed: 01/08/2023] Open
Abstract
Background Heat stress potentially has detrimental effects on brain function. Hence, cognitive function may be impaired during physical activity in a hot environment. Skin cooling is often applied in a hot environment to counteract heat stress. However, it is unclear to what extent neck cooling is effective for cognitive impairment during exercise in a hot environment. The purpose of this study was to examine the effects of temporal neck cooling on cognitive function during strenuous exercise in a hot environment. Methods Eight male young participants (mean ± SD, age = 26.1 ± 3.2 years; peak oxygen uptake = 45.6 ± 5.2 ml/kg/min) performed Spatial delayed response (DR) task (working memory) and Go/No-Go task (executive function) at rest and during exercise in the Hot and Hot + Cooling conditions. After the participants completed the cognitive tasks at rest, they cycled the ergometer until their heart rate (HR) reached 160 beats/min. Then, they cycled for 10 min while keeping their HR at 160 beats/min. The cognitive tasks were performed 3 min after their HR reached 160 beats/min. The air temperature was maintained at 35°C and the relative humidity was controlled at 70%. Neck cooling was applied to the backside of the neck by a wet towel and fanning. We used accuracy of the Spatial DR and Go/No-Go tasks and reaction time in the Go/No-Go task to assess cognitive function. Results Neck cooling temporarily decreased the skin temperature during exercise. The accuracy of the cognitive tasks was lower during exercise than that at rest in the Hot and Hot + Cooling condition (p < 0.05). There were no differences in the accuracy between the Hot and Hot + Cooling conditions (p = 0.98). Neither exercise (p = 0.40) nor cooling (p = 0.86) affected reaction time. These results indicate that temporal neck cooling did not alter cognitive function during strenuous exercise in a hot environment. Conclusions The present study suggests that temporal neck cooling with a wet towel and fanning is not effective for attenuating impairment of working memory and executive function during strenuous exercise with a short duration in a warm and humid environment.
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Affiliation(s)
- Soichi Ando
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan. .,Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
| | - Takaaki Komiyama
- Graduate School of Sports and Health Science, Fukuoka University, Fukuoka, Japan.
| | - Mizuki Sudo
- Fukuoka University Institute for Physical Activity, Fukuoka University, Fukuoka, Japan. .,Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare, Tokyo, Japan.
| | - Akira Kiyonaga
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan. .,Fukuoka University Institute for Physical Activity, Fukuoka University, Fukuoka, Japan.
| | - Hiroaki Tanaka
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan. .,Fukuoka University Institute for Physical Activity, Fukuoka University, Fukuoka, Japan.
| | - Yasuki Higaki
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan. .,Fukuoka University Institute for Physical Activity, Fukuoka University, Fukuoka, Japan.
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Schlader ZJ, Gagnon D, Adams A, Rivas E, Cullum CM, Crandall CG. Cognitive and perceptual responses during passive heat stress in younger and older adults. Am J Physiol Regul Integr Comp Physiol 2015; 308:R847-54. [PMID: 25786484 PMCID: PMC4436980 DOI: 10.1152/ajpregu.00010.2015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/15/2015] [Indexed: 12/22/2022]
Abstract
We tested the hypothesis that attention, memory, and executive function are impaired to a greater extent in passively heat-stressed older adults than in passively heat-stressed younger adults. In a randomized, crossover design, 15 older (age: 69 ± 5 yr) and 14 younger (age: 30 ± 4 yr) healthy subjects underwent passive heat stress and time control trials. Cognitive tests (outcomes: accuracy and reaction time) from the CANTAB battery evaluated attention [rapid visual processing (RVP), choice reaction time (CRT)], memory [spatial span (SSP), pattern recognition memory (PRM)], and executive function [one touch stockings of Cambridge (OTS)]. Testing was undertaken on two occasions during each trial, at baseline and after internal temperature had increased by 1.0 ± 0.2°C or after a time control period. For tests that measured attention, reaction time during RVP and CRT was slower (P ≤ 0.01) in the older group. During heat stress, RVP reaction time improved (P < 0.01) in both groups. Heat stress had no effect (P ≥ 0.09) on RVP or CRT accuracy in either group. For tests that measured memory, accuracy on SSP and PRM was lower (P < 0.01) in the older group, but there was no effect of heat stress (P ≥ 0.14). For tests that measured executive function, overall, accuracy on OTS was lower, and reaction time was slower in the older group (P ≤ 0.05). Reaction time generally improved during heat stress, but there was no effect of heat stress on accuracy in either group. These data indicate that moderate increases in body temperature during passive heat stress do not differentially compromise cognitive function in younger and older adults.
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Affiliation(s)
- Zachary J Schlader
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Daniel Gagnon
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Amy Adams
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Eric Rivas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Kinesiology, Texas Woman's University, Denton, Texas; and
| | - C Munro Cullum
- Departments of Psychiatry and Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas;
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Preservation of cognitive performance with age during exertional heat stress under low and high air velocity. BIOMED RESEARCH INTERNATIONAL 2015; 2015:619103. [PMID: 25874223 PMCID: PMC4385631 DOI: 10.1155/2015/619103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/05/2014] [Indexed: 11/26/2022]
Abstract
Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements. Purpose. To examine the effects of age and increased air velocity, during exercise in humid heat, on information processing and attention. Methods. Nine young (24 ± 1 years) and 9 older (59 ± 1 years) males cycled 4 × 15 min (separated by 15 min rest) at a fixed rate of heat production (400 W) in humid heat (35°C, 60% relative humidity) under 0.5 (low) and 3.0 (high) m·s−1 air velocity wearing coveralls. At rest, immediately following exercise (end exercise), and after the final recovery, participants performed an abbreviated paced auditory serial addition task (PASAT, 2 sec pace). Results. PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms. Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition. Conclusion. No significant decrements in attention and speeded information processing were observed, with age or altered air velocity, following intermittent exercise in humid heat.
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Inside the ‘Hurt Locker’: The Combined Effects of Explosive Ordnance Disposal and Chemical Protective Clothing on Physiological Tolerance Time in Extreme Environments. ANNALS OF OCCUPATIONAL HYGIENE 2015; 59:922-31. [DOI: 10.1093/annhyg/mev029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 03/09/2015] [Indexed: 12/30/2022]
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Chan AP, Song W, Yang Y. Meta-analysis of the effects of microclimate cooling systems on human performance under thermal stressful environments: Potential applications to occupational workers. J Therm Biol 2015; 49-50:16-32. [DOI: 10.1016/j.jtherbio.2015.01.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 11/25/2022]
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Pyke AJ, Costello JT, Stewart IB. Heat strain evaluation of overt and covert body armour in a hot and humid environment. APPLIED ERGONOMICS 2015; 47:11-15. [PMID: 25479969 DOI: 10.1016/j.apergo.2014.08.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/07/2014] [Accepted: 08/13/2014] [Indexed: 06/04/2023]
Abstract
UNLABELLED The aim of this study was to elucidate the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. Eight healthy males walked on a treadmill for 120 min at 22% of their heart rate reserve in a climate chamber simulating 31 °C (60%RH) wearing either no armour (control), overt or covert PBA in addition to a security guard uniform, in a randomised controlled crossover design. No significant difference between conditions at the end of each trial was observed in core temperature, heart rate or skin temperature (P > 0.05). Covert PBA produced a significantly greater amount of body mass change (-1.81 ± 0.44%) compared to control (-1.07 ± 0.38%, P = 0.009) and overt conditions (-1.27 ± 0.44%, P = 0.025). Although a greater change in body mass was observed after the covert PBA trial; based on the physiological outcome measures recorded, the heat strain encountered while wearing lightweight, non-military overt or covert PBA was negligible compared to no PBA. PRACTITIONER SUMMARY The wearing of bullet proof vests or body armour is a requirement of personnel engaged in a wide range of occupations including police, security, customs and even journalists in theatres of war. This randomised controlled crossover study is the first to examine the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. We conclude that the heat strain encountered while wearing both overt and covert lightweight, non-military PBA was negligible compared to no PBA.
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Affiliation(s)
- Andrew J Pyke
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia.
| | - Joseph T Costello
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia.
| | - Ian B Stewart
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia.
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Parvari RA, Aghaei HA, Dehghan H, Khademi A, Maracy MR, Dehghan SF. The Effect of Fabric Type of Common Iranian Working Clothes on the Induced Cardiac and Physiological Strain Under Heat Stress. ARCHIVES OF ENVIRONMENTAL & OCCUPATIONAL HEALTH 2015; 70:272-278. [PMID: 24971773 DOI: 10.1080/19338244.2014.891965] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The present study compared the effect of fabric type of working clothes on heat strain responses in different levels of physical workload and under different kinds of weather conditions. Four kinds of working clothing fabric that are greatly popular in Iranian industry were assessed on 18 healthy male at 2 environments: hot and humid (dry temperature [DBt]: 35°C and relative humidity [RH]: 70%) and hot and dry (DBt: 40°C and RH: 40%). The physiological responses such as heart rate and core body temperature were reported. It was found that there were no significant differences between different types of clothing fabric on cardiac and physiological parameters. It can be recommended that 100% cotton clothing ensemble during low-workload activities and 30.2% cotton-69.8% polyester clothing ensemble during moderate-workload activities is used for Iranian workers to maintain the cardiac and physiological strains as low as possible.
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Affiliation(s)
- Roh Allah Parvari
- a Department of Occupational Health Engineering, School of Health , Isfahan University of Medical Sciences , Isfahan , Iran
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LEE JY, PARK J, PARK H, COCA A, KIM JH, TAYLOR NA, SON SY, TOCHIHARA Y. What do firefighters desire from the next generation of personal protective equipment? Outcomes from an international survey. INDUSTRIAL HEALTH 2015; 53:434-44. [PMID: 26027710 PMCID: PMC4591136 DOI: 10.2486/indhealth.2015-0033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The purpose of this study was to investigate smart features required for the next generation of personal protective equipment (PPE) for firefighters in Australia, Korea, Japan, and the USA. Questionnaire responses were obtained from 167 Australian, 351 Japanese, 413 Korean, and 763 U.S. firefighters (1,611 males and 61 females). Preferences concerning smart features varied among countries, with 27% of Korean and 30% of U.S. firefighters identifying 'a location monitoring system' as the most important element. On the other hand, 43% of Japanese firefighters preferred 'an automatic body cooling system' while 21% of the Australian firefighters selected equally 'an automatic body cooling system' and 'a wireless communication system'. When asked to rank these elements in descending priority, responses across these countries were very similar with the following items ranked highest: 'a location monitoring system', 'an automatic body cooling system', 'a wireless communication system', and 'a vision support system'. The least preferred elements were 'an automatic body warming system' and 'a voice recording system'. No preferential relationship was apparent for age, work experience, gender or anthropometric characteristics. These results have implications for the development of the next generation of PPE along with the international standardisation of the smart PPE.
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Affiliation(s)
- Joo-Young LEE
- Department of Textiles, Merchandising and Fashion Design,
Seoul National University, Republic of Korea
- *To whom correspondence should be addressed. E-mail:
| | - Joonhee PARK
- Department of Textiles, Merchandising and Fashion Design,
Seoul National University, Republic of Korea
| | - Huiju PARK
- Department of Fiber Science & Apparel Design, Cornell
University, USA
| | - Aitor COCA
- National Personal Protective Technology Laboratory, National
Institute for Occupational Safety and Health, Centers for Disease Control and Prevention,
USA
| | - Jung-Hyun KIM
- National Personal Protective Technology Laboratory, National
Institute for Occupational Safety and Health, Centers for Disease Control and Prevention,
USA
| | - Nigel A.S. TAYLOR
- Centre for Human and Applied Physiology, School of Medicine,
University of Wollongong, Australia
| | - Su-Young SON
- Human Engineering and Risk Management Research Group,
National Institute of Occupational Safety and Health, Japan
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