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Flouris AD, Notley SR, Stearns RL, Casa DJ, Kenny GP. Recommended water immersion duration for the field treatment of exertional heat stroke when rectal temperature is unavailable. Eur J Appl Physiol 2024; 124:479-490. [PMID: 37552243 DOI: 10.1007/s00421-023-05290-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/14/2023] [Indexed: 08/09/2023]
Abstract
INTRODUCTION The recommended treatment for exertional heat stroke is immediate, whole-body immersion in < 10 °C water until rectal temperature (Tre) reaches ≤ 38.6 °C. However, real-time Tre assessment is not always feasible or available in field settings or emergency situations. We defined and validated immersion durations for water temperatures of 2-26 °C for treating exertional heat stroke. METHODS We compiled data for 54 men and 18 women from 7 previous laboratory studies and derived immersion durations for reaching 38.6 °C Tre. The resulting immersion durations were validated against the durations of cold-water immersion used to treat 162 (98 men; 64 women) exertional heat stroke cases at the Falmouth Road Race between 1984 and 2011. RESULTS Age, height, weight, body surface area, body fat, fat mass, lean body mass, and peak oxygen uptake were weakly associated with the cooling time to a safe Tre of 38.6 °C during immersions to 2-26 °C water (R2 range: 0.00-0.16). Using a specificity criterion of 0.9, receiver operating characteristics curve analysis showed that exertional heat stroke patients must be immersed for 11-12 min when water temperature is ≤ 9 °C, and for 18-19 min when water temperature is 10-26 °C (Cohen's Kappa: 0.32-0.75, p < 0.001; diagnostic odds ratio: 8.63-103.27). CONCLUSION The reported immersion durations are effective for > 90% of exertional heat stroke patients with pre-immersion Tre of 39.5-42.8 °C. When available, real-time Tre monitoring is the standard of care to accurately diagnose and treat exertional heat stroke, avoiding adverse health outcomes associated with under- or over-cooling, and for implementing cool-first transport second exertional heat stroke policies.
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Affiliation(s)
- Andreas D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Defence Science and Technology Group, Melbourne, VIC, Australia
| | - Rebecca L Stearns
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT, USA
| | - Douglas J Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT, USA
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada.
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.
- Montpetit Hall, 125 University Private, Room 367, Ottawa, ON, K1N 6N5, Canada.
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Yang S, Wang L, Zhang H, Yang J, Li W, Zhang Y. Field study on pregnant women's thermal preference in different trimesters in winter. J Therm Biol 2023; 118:103744. [PMID: 37988914 DOI: 10.1016/j.jtherbio.2023.103744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 11/23/2023]
Abstract
This study investigated the differences in the thermal preferences of pregnant women during various trimesters and the factors influencing these preferences. The survey was conducted in a hospital waiting room, encompassing the testing of thermal environmental parameters, and the distribution of questionnaires to pregnant women. These questionnaires encompassed various aspects, including basic information, thermal responses, pregnancy diseases, and more. In total, 1388 questionnaires were collected, distributed across the first trimester (225 participants), second trimester (498 participants), and third trimester (665 participants). The findings revealed a notable shift in the thermal preferences of pregnant women as their pregnancies progressed, transitioning from a preference for warmer conditions to a preference for cooler environments. Specifically, the mean thermal preference scores for the first, second, and third trimesters were 0.82, -0.27, and -1.76, respectively. These shifting preferences were associated with various factors, including pregnancy diseases, pre-pregnancy body mass index (PBMI), and exercise habits. Notably, hyperthyroidism, a higher PBMI, and regular exercise were correlated with a preference for cooler conditions, whereas hypothyroidism, anemia, a lower PBMI, and rare exercise were associated with a preference for warmer environments. Furthermore, it was observed that the actual neutral temperatures for pregnant women in the first, second, and third trimesters were 20.3 °C, 19.5 °C, and 19 °C, respectively. By contrast, the predicted neutral temperatures were 23.5 °C for the first and third trimesters and 23.4 °C for the second trimester. This indicated that the Predicted Mean Vote (PMV) model tended to underestimate the acceptability that pregnant women experienced in colder environments. Given the unique thermal preferences of pregnant women, further research is essential to refine thermal comfort parameters and the PMV model tailored specifically to this demographic.
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Affiliation(s)
- Sijin Yang
- College of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Lijuan Wang
- College of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Hui Zhang
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an, 710004, China
| | - Ji Yang
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an, 710004, China.
| | - Wenhui Li
- College of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Yijin Zhang
- College of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an, 710048, China
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Pryor RR, Haboian K, Fitts T, Stooks JJ. Tarp-Assisted Cooling for Exertional Heat Stroke Treatment in Wildland Firefighting. Wilderness Environ Med 2023; 34:490-497. [PMID: 37748988 DOI: 10.1016/j.wem.2023.08.002] [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: 06/06/2023] [Revised: 07/26/2023] [Accepted: 08/08/2023] [Indexed: 09/27/2023]
Abstract
INTRODUCTION Exertional heat stroke is a life-threatening emergency necessitating immediate treatment with rapid body cooling. A field-expedient alternative may be tarp-assisted cooling, requiring only water and a tarp. The objective of this study was to compare core temperature (Tc) cooling rates of tarp-assisted cooling using the limited resources available to a wildland firefighter and the current standard care provided in wilderness settings. METHODS This cross-over, randomized control trial of 17 healthy individuals consisted of exercise in a 42±1°C, 32±4% relative humidity environment while wearing wildland firefighter attire, followed by cooling. Body cooling consisted of either pouring 11 L of 25±1°C water over the torso while lying supine on a tarp configured to hold water close to the individual (Tarp) or dousing the water on the participant followed by lying supine with a light breeze, current standard care in the wilderness (Current Care). Cooling occurred until Tc reached 38°C. RESULTS Participants walked until a similar Tc was achieved in Tarp (39.59±0.04°C) and Current Care (39.55±0.22°C; P=0.36). Core temperature cooling rate was not different between Tarp (0.076±0.042°C·min-1) and Current Care (0.088±0.046°C·min-1; P=0.41). CONCLUSIONS In hyperthermic individuals, Tarp did not provide a faster cooling rate compared to the current exertional heat stroke care provided in the wilderness, and both provided a slower cooling rate than that provided by the traditional method of cold water immersion (>0.20°C·min-1) to treat exertional heat stroke patients.
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Affiliation(s)
- Riana R Pryor
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY.
| | - Kara Haboian
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY
| | - Triniti Fitts
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY
| | - Jocelyn J Stooks
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY
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Hutchins KP, Minett GM, Stewart IB. Treating exertional heat stroke: Limited understanding of the female response to cold water immersion. Front Physiol 2022; 13:1055810. [PMID: 36505067 PMCID: PMC9732943 DOI: 10.3389/fphys.2022.1055810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 11/02/2022] [Indexed: 11/26/2022] Open
Abstract
According to an expansive body of research and best practice statements, whole-body cold water immersion is the gold standard treatment for exertional heat stroke. However, as this founding evidence was predominantly drawn from males, the current guidelines for treatment are being applied to women without validation. Given the recognised differences in thermal responses experienced by men and women, all-encompassing exertional heat stroke treatment advice may not effectively protect both sexes. In fact, recent evidence suggests that hyperthermic women cool faster than hyperthermic men during cold water immersion. This raises the question of whether overcooling is risked if the present guidelines are followed. The current mini-review examined the literature on women's response to cold water immersion as a treatment for exertional heat stroke and aimed to clarify whether the current guidelines have appropriately considered research investigating women. The potential implications of applying these guidelines to women were also discussed.
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IWATA R, CHANG L, AKIYAMA H, KAWAMURA T, SUZUKI K, SAKAMOTO S, MURAOKA I. The effects of sex differences on delayed-onset muscle soreness by cold-water immersion following resistance exercise. GAZZETTA MEDICA ITALIANA ARCHIVIO PER LE SCIENZE MEDICHE 2022. [DOI: 10.23736/s0393-3660.20.04328-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Koenig FS, Miller KC, O'Connor P, Amaria N. Body Anthropometrics and Rectal Temperature Cooling Rates in Women With Hyperthermia. J Athl Train 2022; 57:464-469. [PMID: 35230443 PMCID: PMC9205556 DOI: 10.4085/1062-6050-225-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Cold-water immersion (CWI) is the best treatment for exertional heat stroke (EHS), and rectal temperature (Trec) cooling rates may differ between sexes. Previous authors have suggested body surface area (BSA) to lean body mass (LBM) ratio is the largest factor affecting CWI Trec cooling rates in men with hyperthermia; this has never been confirmed in women with hyperthermia. OBJECTIVE To examine whether the BSA:LBM ratio and other anthropometrics affect Trec cooling rates in women with hyperthermia. DESIGN Cross-sectional study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Sixteen women were placed in either a low BSA:LBM ratio (LOW; n = 8; age = 22 ± 1 years, height = 166.8 ± 6.0 cm, mass = 64.1 ± 4.5 kg, BSA:LBM ratio = 3.759 ± 0.214 m2/kg·102) or high BSA:LBM ratio group (HIGH; n = 8; age = 22 ± 2 years, height = 162.7 ± 8.9 cm, mass = 65.8 ± 12.7 kg, BSA:LBM ratio = 4.161 ± 0.232 m2/kg·102). INTERVENTION(S) On day 1, we measured physical characteristics using dual-energy x-ray absorptiometry, and participants completed a maximal oxygen consumption test. On day 2, participants walked at 4.8 km/h for 3 minutes and then ran at 80% of their predetermined maximal oxygen consumption for 2 minutes in the heat (temperature = ~40°C, relative humidity = 40%). This sequence was repeated until Trec reached 39.5°C. Then, they completed CWI (temperature = ~10°C) until Trec was 38°C. MAIN OUTCOME MEASURE(S) Rectal temperature and CWI cooling rates. RESULTS Groups had different BSA:LBM ratios (P = .001), body fat percentages (LOW: 25.7% ± 5.0%; HIGH: 33.7% ± 6.3%; P = .007), and LBM (LOW: 45.8 ± 3.0 kg; HIGH: 41.0 ± 5.1 kg; P = .02) but not different BSA (LOW: 1.72 ± 0.08 m2; HIGH: 1.70 ± 0.16 m2; P = .40) or BMI (LOW: 23.1 ± 2.1; HIGH: 24.9 ± 4.7; P = .17). Despite differences in several physical characteristics, Trec cooling rates were excellent but comparable (LOW: 0.26°C/min ± 0.09°C/min; HIGH: 0.27°C/min ± 0.07°C/min; P = .39). The BSA:LBM ratio (r = 0.14, P = .59), body fat percentage (r = 0.29, P = .28), LBM (r = -0.10, P = .70), BSA (r = -0.01, P = .97), and BMI (r = 0.37, P = .16) were not correlated with Trec cooling rates. CONCLUSIONS Body anthropometrics did not affect CWI Trec cooling rates in women with hyperthermia. Clinicians need not worry about anthropometric characteristics slowing the treatment of severe hyperthermia in women using CWI.
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Affiliation(s)
- Fallon S Koenig
- *School of Health Sciences, Central Michigan University, Mount Pleasant
| | - Kevin C Miller
- †School of Rehabilitation and Medical Sciences, Central Michigan University, Mount Pleasant
| | - Paul O'Connor
- *School of Health Sciences, Central Michigan University, Mount Pleasant
| | - Noshir Amaria
- ‡College of Medicine, Central Michigan University, Mount Pleasant
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Roberts WO, Armstrong LE, Sawka MN, Yeargin SW, Heled Y, O'Connor FG. ACSM Expert Consensus Statement on Exertional Heat Illness: Recognition, Management, and Return to Activity. Curr Sports Med Rep 2021; 20:470-484. [PMID: 34524191 DOI: 10.1249/jsr.0000000000000878] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
ABSTRACT Exertional heat stroke (EHS) is a true medical emergency with potential for organ injury and death. This consensus statement emphasizes that optimal exertional heat illness management is promoted by a synchronized chain of survival that promotes rapid recognition and management, as well as communication between care teams. Health care providers should be confident in the definitions, etiologies, and nuances of exertional heat exhaustion, exertional heat injury, and EHS. Identifying the athlete with suspected EHS early in the course, stopping activity (body heat generation), and providing rapid total body cooling are essential for survival, and like any critical life-threatening situation (cardiac arrest, brain stroke, sepsis), time is tissue. Recovery from EHS is variable, and outcomes are likely related to the duration of severe hyperthermia. Most exertional heat illnesses can be prevented with the recognition and modification of well-described risk factors ideally addressed through leadership, policy, and on-site health care.
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Affiliation(s)
- William O Roberts
- Department of Family Medicine and Community Health, University of Minnesota Medical School, Minneapolis, MN
| | | | - Michael N Sawka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA
| | - Susan W Yeargin
- Department of Exercise Science, University of South Carolina, Columbia, SC
| | - Yuval Heled
- Clinical and Integrative Physiology Unit, Heller Institute of Medical Research, Sheba Medical Center, ISRAEL
| | - Francis G O'Connor
- Consortium for Health and Military Performance, Uniformed Services University of the Health Sciences, Bethesda, MD
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Iwata R, Kawamura T, Hosokawa Y, Chang L, Suzuki K, Muraoka I. Comparison of the effect of post-exercise cooling with ice slurry ingestion between males and females. J Therm Biol 2021; 99:102979. [PMID: 34420623 DOI: 10.1016/j.jtherbio.2021.102979] [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: 03/16/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 11/18/2022]
Abstract
This study aimed to compare the effects of ice slurry ingestion on post-exercise cooling in males and females. Twenty-four healthy adults (male n = 12; body weight [BW], 65.8 ± 10.3 kg; female, n = 12; BW, 58.2 ± 10.0 kg) participated in this study. Participants ingested 7.5 g/kg of either ice slurry at -1 °C (ICE) or control fluid at 20 °C (CON) during recovery after cycling at 55% VO2max until the rectal temperature reached 38.5 °C or exhaustion in a hot environment (controlled at 38 °C, 40% relative humidity). Rectal (Tre) and skin (Tsk) temperature, ratings of thermal sensation (TS), thermal comfort (TC), heart rate (HR), mean arterial pressure (MAP), and whole body sweat loss (WBSL) were measured 60 min after exercise. Ice slurry ingestion reduced Tre and TS and improved post-exercise hypotension only in females (p < 0.05). In comparison, males did not receive cooling effect from post- exercise cooling with ice slurry ingestion. WBSL tended to be lower in ICE than CON in males (ICE, 454.3 ± 172.3 g; CON, 539.7 ± 157.2 g; p = 0.065). In conclusion, sex differences were observed in the effects of post-exercise cooling with ice slurry ingestion.
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Affiliation(s)
- Risa Iwata
- Japan Institute of Sport Sciences, Tokyo, Japan; Graduate School of Sport Sciences, Waseda University, Saitama, Japan.
| | - Takuji Kawamura
- Waseda Institute for Sport Sciences, Saitama 359-1192, Japan
| | - Yuri Hosokawa
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
| | - Lili Chang
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | | | - Isao Muraoka
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
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Miller KC, Casa DJ, Adams WM, Hosokawa Y, Cates J, Emrich C, Fitzpatrick T, Hopper M, Jardine JF, LaBotz M, Lopez RM, O'Connor F, Smith MS. Roundtable on Preseason Heat Safety in Secondary School Athletics: Prehospital Care of Patients With Exertional Heat Stroke. J Athl Train 2021; 56:372-382. [PMID: 33290540 PMCID: PMC8063668 DOI: 10.4085/1062-6050-0173.20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE First, we will update recommendations for the prehospital management and care of patients with exertional heat stroke (EHS) in the secondary school setting. Second, we provide action items to aid clinicians in developing best-practice documents and policies for EHS. Third, we supply practical strategies clinicians can use to implement best practice for EHS in the secondary school setting. DATA SOURCES An interdisciplinary working group of scientists, physicians, and athletic trainers evaluated the current literature regarding the prehospital care of EHS patients in secondary schools and developed this narrative review. When published research was nonexistent, expert opinion and experience guided the development of recommendations for implementing life-saving strategies. The group evaluated and further refined the action-oriented recommendations using the Delphi method. CONCLUSIONS Exertional heat stroke continues to be a leading cause of sudden death in young athletes and the physically active. This may be partly due to the numerous barriers and misconceptions about the best practice for diagnosing and treating patients with EHS. Exertional heat stroke is survivable if it is recognized early and appropriate measures are taken before patients are transported to hospitals for advanced medical care. Specifically, best practice for EHS evaluation and treatment includes early recognition of athletes with potential EHS, a rectal temperature measurement to confirm EHS, and cold-water immersion before transport to a hospital. With planning, communication, and persistence, clinicians can adopt these best-practice recommendations to aid in the recognition and treatment of patients with EHS in the secondary school setting.
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Affiliation(s)
- Kevin C. Miller
- School of Rehabilitation and Medical Sciences, Central Michigan University, Mount Pleasant
| | - Douglas J. Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs
| | - William M. Adams
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Yuri Hosokawa
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | | | | | | | | | - John F. Jardine
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs
| | | | - Rebecca M. Lopez
- Department of Orthopaedics and Sports Medicine, University of South Florida, Tampa
| | - Francis O'Connor
- Department of Military and Emergency Medicine, Uniformed Services University, Bethesda, MD
| | - M. Seth Smith
- Department of Orthopedics and Rehabilitation, University of Florida, Gainesville
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First aid cooling techniques for heat stroke and exertional hyperthermia: A systematic review and meta-analysis. Resuscitation 2020; 148:173-190. [PMID: 31981710 DOI: 10.1016/j.resuscitation.2020.01.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/02/2020] [Indexed: 01/29/2023]
Abstract
BACKGROUND Heat stroke is an emergent condition characterized by hyperthermia (>40 °C/>104 °F) and nervous system dysregulation. There are two primary etiologies: exertional which occurs during physical activity and non-exertional which occurs during extreme heat events without physical exertion. Left untreated, both may lead to significant morbidity, are considered a special circumstance for cardiac arrest, and cause of mortality. METHODS We searched Medline, Embase, CINAHL and SPORTDiscus. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods and risk of bias assessments to determine the certainty and quality of evidence. We included randomized controlled trials, non-randomized trials, cohort studies and case series of five or more patients that evaluated adults and children with non-exertional or exertional heat stroke or exertional hyperthermia, and any cooling technique applicable to first aid and prehospital settings. Outcomes included: cooling rate, mortality, neurological dysfunction, adverse effects and hospital length of stay. RESULTS We included 63 studies, of which 37 were controlled studies, two were cohort studies and 24 were case series of heat stroke patients. Water immersion of adults with exertional hyperthermia [cold water (14-17 °C/57.2-62.6 °F), colder water (8-12 °C/48.2-53.6 °F) and ice water (1-5 °C/33.8-41 °F)] resulted in faster cooling rates when compared to passive cooling. No single water temperature range was found to be associated with a quicker core temperature reduction than another (cold, colder or ice). CONCLUSION Water immersion techniques (using 1-17 °C water) more effectively lowered core body temperatures when compared with passive cooling, in hyperthermic adults. The available evidence suggests water immersion can rapidly reduce core body temperature in settings where it is feasible.
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Does Gender Affect Rectal Temperature Cooling Rates? A Critically Appraised Topic. J Sport Rehabil 2019; 28:522-525. [DOI: 10.1123/jsr.2018-0081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Effects of Intravenous Cold Saline on Hyperthermic Athletes Representative of Large Football Players and Small Endurance Runners. Clin J Sport Med 2018; 28:493-499. [PMID: 29112514 DOI: 10.1097/jsm.0000000000000505] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To evaluate the cooling effects of intravenous (IV) cold normal (0.9%) saline on hyperthermic athletes. DESIGN Randomized crossover study design. SETTING Controlled research laboratory. PARTICIPANTS Twelve male participants who were representative of a collegiate cross-country (6) and American football (6) population. INTERVENTIONS Participants underwent body composition analysis using a BodPod. They were placed in an environmentally controlled chamber and brought to a Tc of 39.5°C with dynamic exercise. When temperatures were reached, they were treated with either 2 L of cold saline (CS) (4°C) or intravenous room temperature (22°C) saline (RS) over a ∼30-minute period. Tre was measured with a rectal temperature probe every minute during the treatment period. MAIN OUTCOME MEASURES Total ΔTre (ending Tre - starting Tre) and cooling rate (total change in Tre/time) were measured for each condition, and body composition variables calculated included body surface area (BSA), BSA-to-mass ratio (BSA/mass), lean body mass, and body fat percentage (%BF) (P < 0.05). RESULTS Statistically significant differences were found in the total ΔTre and cooling rate between the CS and RS trials. The cooling rate for the CS trials was significantly correlated to mass, BSA, BSA/mass, and %BF. CONCLUSIONS In hyperthermic athletes, core temperature was reduced more effectively using chilled saline during IV infusion. Body composition had a significant impact on overall cooling revealing that the smaller and leaner participants cooled at a greater rate. When indicated, CS infusion could be considered for cooling hyperthermic individuals when other methods are not available.
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Poirier MP, Notley SR, Flouris AD, Kenny GP. Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia. Appl Physiol Nutr Metab 2018. [PMID: 29529383 DOI: 10.1139/apnm-2017-0619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2 °C) following exertional hyperthermia (rectal temperature ≥39.5 °C) in a physically heterogeneous group of men and women (n = 62). Lean body mass was the only significant predictor of cooling time following CWI (R2 = 0.137; P < 0.001); however, that prediction did not provide the precision (mean residual square error: 3.18 ± 2.28 min) required to act as a safe alternative to rectal temperature measurements.
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Affiliation(s)
- Martin P Poirier
- a Human and Environmental Physiological Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Sean R Notley
- a Human and Environmental Physiological Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Andreas D Flouris
- b FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, 42100, Greece
| | - Glen P Kenny
- c Human and Environmental Physiological Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.,d Human and Environmental Physiological Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.,e Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada
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Abstract
Excised fat tissue has a lower thermal conductivity than excised lean tissue. In theory then subcutaneous fat might serve as a barrier to heat loss and influence thermoregulatory abilities. In some aquatic mammals and animals from severely cold habitats subcutaneous adipose tissue has evolved into a continuous sheet that envelopes the organs and acts as a thermal insulation layer. This layer can comprise more than half of the cross-sectional area of the body. In most mammals however, the distribution of fat is less continuous. It has been suggested that in tropical animals this distribution may in fact allow animals to still store energy while not impeding heat loss. Studies of humans immersed in cool water convincingly demonstrate that obesity in humans also serves an insulation function. Humans with obesity cool less rapidly and have to elevate their metabolism less significantly than lean individuals when immersed in water. Although obesity provides an advantage in cold conditions it conversely impedes heat loss and makes obese people susceptible to heat stress more than lean individuals. In small mammals like mice the role of subcutaneous (or intradermal) fat for providing thermal insulation is less clear. In theory variations in thermoregulatory capacity may allow individuals different capabilities to burn off excess consumption. Hence, thermoregulatory variations may cause obesity differences. Thermoregulatory capacity is related to ambient temperature. Yet, levels of obesity are only weakly related to ambient temperature and this effect disappears when confounding factors like poverty and race are taken into account. Hence we conclude that obesity may have a significant impact on thermoregulatory physiology, but the converse is much less likely.
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Zandvoort CS, de Zwart JR, van Keeken BL, Viroux PJF, Tiemessen IJH. A customised cold-water immersion protocol favours one-size-fits-all protocols in improving acute performance recovery. Eur J Sport Sci 2017; 18:54-61. [PMID: 29072114 DOI: 10.1080/17461391.2017.1386718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The purpose of the present study was to investigate whether a customised cold-water immersion (CWIc) protocol was more effective in enhancing acute performance recovery than a one-size-fits-all CWI (CWIs) or active recovery (AR) protocol. On three separate testing days, 10 healthy, physically active, non-smoking males completed the same fatiguing protocol (60 squat jumps and a 2'30″ all-out cycling time-trial) followed by CWIc (12°C, 10-17 min), CWIs (15°C, 10 min) or AR (60 W, 10 min). Outcome measures to assess acute recovery were heart rate variability (HRV) as HRVrecovery, muscle power (MP) as absolute and relative decline, and muscle soreness (MS) at 0 and 24 h. HRVrecovery for CWIc was significantly higher compared to CWIs (p = .026, r = 0.74) and AR (p = .000, r = 0.95). The relative decline in MP after CWIc was significantly lower than after CWIs (p = .017, r = 0.73). MS 0 h and MS 24 h post-intervention were not different after CWIc compared to CWIs and AR (p > .05). The findings of the present study demonstrated that CWIc outperforms CWIs and AR in the acute recovery of cardiovascular (HRV) and CWIs in neuromuscular (MP) performance with no differences in MS. To optimise the effects of CWI, contributions of the protocol duration and water temperature should be considered to guarantee an optimal customised dose.
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Affiliation(s)
- Coen S Zandvoort
- a Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences , Vrije Universiteit, Amsterdam Movement Sciences , Amsterdam , The Netherlands
| | - Jelmer R de Zwart
- a Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences , Vrije Universiteit, Amsterdam Movement Sciences , Amsterdam , The Netherlands
| | - Brenda L van Keeken
- a Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences , Vrije Universiteit, Amsterdam Movement Sciences , Amsterdam , The Netherlands
| | | | - Ivo J H Tiemessen
- b Mobilito Sport , Amsterdam , The Netherlands.,c ProCcare , Halle-Zoersel , Belgium
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Godek SF, Morrison KE, Scullin G. Cold-Water Immersion Cooling Rates in Football Linemen and Cross-Country Runners With Exercise-Induced Hyperthermia. J Athl Train 2017; 52:902-909. [PMID: 28937782 PMCID: PMC5687234 DOI: 10.4085/1062-6050-52.7.08] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Ideal and acceptable cooling rates in hyperthermic athletes have been established in average-sized participants. Football linemen (FBs) have a small body surface area (BSA)-to-mass ratio compared with smaller athletes, which hinders heat dissipation. OBJECTIVE To determine cooling rates using cold-water immersion in hyperthermic FBs and cross-country runners (CCs). DESIGN Cohort study. SETTING Controlled university laboratory. PATIENTS OR OTHER PARTICIPANTS Nine FBs (age = 21.7 ± 1.7 years, height = 188.7 ± 4 cm, mass = 128.1 ± 18 kg, body fat = 28.9% ± 7.1%, lean body mass [LBM] = 86.9 ± 19 kg, BSA = 2.54 ± 0.13 m2, BSA/mass = 201 ± 21.3 cm2/kg, and BSA/LBM = 276.4 ± 19.7 cm2/kg) and 7 CCs (age = 20 ± 1.8 years, height = 176 ± 4.1 cm, mass = 68.7 ± 6.5 kg, body fat = 10.2% ± 1.6%, LBM = 61.7 ± 5.3 kg, BSA = 1.84 ± 0.1 m2, BSA/mass = 268.3 ± 11.7 cm2/kg, and BSA/LBM = 298.4 ± 11.7 cm2/kg). INTERVENTION(S) Participants ingested an intestinal sensor, exercised in a climatic chamber (39°C, 40% relative humidity) until either target core temperature (Tgi) was 39.5°C or volitional exhaustion was reached, and were immediately immersed in a 10°C circulated bath until Tgi declined to 37.5°C. A general linear model repeated-measures analysis of variance and independent t tests were calculated, with P < .05. MAIN OUTCOME MEASURE(S) Physical characteristics, maximal Tgi, time to reach 37.5°C, and cooling rate. RESULTS Physical characteristics were different between groups. No differences existed in environmental measures or maximal Tgi (FBs = 39.12°C ± 0.39°C, CCs = 39.38°C ± 0.19°C; P = .12). Cooling times required to reach 37.5°C (FBs = 11.4 ± 4 minutes, CCs = 7.7 ± 0.06 minutes; P < .002) and therefore cooling rates (FBs = 0.156°C·min-1 ± 0.06°C·min-1, CCs = .255°C·min-1 ± 0.05°C·min-1; P < .002) were different. Strong correlations were found between cooling rate and body mass (r = -0.76, P < .001), total BSA (r = -0.74, P < .001), BSA/mass (r = 0.73, P < .001), LBM/mass (r = 0.72, P < .002), and LBM (r = -0.72, P < .002). CONCLUSIONS With cold-water immersion, the cooling rate in CCs (0.255°C·min-1) was greater than in FBs (0.156°C·min-1); however, both were considered ideal (≥0.155°C·min-1). Athletic trainers should realize that it likely takes considerably longer to cool large hyperthermic American-football players (>11 minutes) than smaller, leaner athletes (7.7 minutes). Cooling rates varied widely from 0.332°C·min-1 in a small runner to only 0.101°C·min-1 in a lineman, supporting the use of rectal temperature for monitoring during cooling.
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Cernych M, Baranauskiene N, Eimantas N, Kamandulis S, Daniuseviciute L, Brazaitis M. Physiological and Psychological Responses during Exercise and Recovery in a Cold Environment Is Gender-Related Rather Than Fabric-Related. Front Psychol 2017; 8:1344. [PMID: 28824518 PMCID: PMC5545600 DOI: 10.3389/fpsyg.2017.01344] [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: 06/07/2017] [Accepted: 07/24/2017] [Indexed: 01/17/2023] Open
Abstract
We evaluated gender-specific effects of two types of undergarments on exercise-induced physiological and psychological stress and subsequent recovery in cold conditions for male and female participants. Ten healthy men and eleven healthy women (25.0 ± 1.5 versus 23.4 ± 1.2 years old, respectively) completed the experimental session twice with two different types of undergarments: polyester or merino wool leggings and long-sleeve tops; specifically, merino fabric had greater thermal resistance and water absorbency, and less water vapor as well as air permeability than polyester. Experimental sessions involved performing 1 h of exercise on a cycle ergometer at 8°C ambient temperature and 55% relative humidity, holding at 70-80 revolutions per minute and 60% of each participant's predetermined maximal power output (assessed by maximal oxygen uptake test), followed by 1 h recovery in the same environment. Every 5 min during exercise and every 10 min during recovery, rectal temperature, heart rate, subjective ratings for thermal, shivering/sweating and clothing wetness sensations, and clothing next-to-skin and outer side surface temperature and humidity on the chest, back and thigh were recorded. All participants experienced high physiological stress (assessed by physiological strain index) during exercise. No significant gender differences were found in core temperature or heart rate changes during exercise, but women cooled down faster during recovery. Next-to-skin humidity was similar between genders and different garment sets during exercise and recovery, but such temperatures at the chest during exercise and at the thigh during exercise and recovery were lower in women with both sets of garments. Subjective thermal sensations were similar in all cases. In the last 20 min of cycling, women started to feel wetter than men (P < 0.05) for both garment sets. Shivering was reported as stronger in women in the last 10 min of recovery. Most of the changes in the garment microclimates during exercise and recovery in the cold were associated with gender-related differences rather than with fabric-related differences.
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Affiliation(s)
- Margarita Cernych
- Institute of Sport Science and Innovations, Lithuanian Sports UniversityKaunas, Lithuania
| | - Neringa Baranauskiene
- Institute of Sport Science and Innovations, Lithuanian Sports UniversityKaunas, Lithuania
| | - Nerijus Eimantas
- Institute of Sport Science and Innovations, Lithuanian Sports UniversityKaunas, Lithuania
| | - Sigitas Kamandulis
- Institute of Sport Science and Innovations, Lithuanian Sports UniversityKaunas, Lithuania
| | - Laura Daniuseviciute
- Faculty of Social Sciences, Arts and Humanities, Kaunas University of TechnologyKaunas, Lithuania
| | - Marius Brazaitis
- Institute of Sport Science and Innovations, Lithuanian Sports UniversityKaunas, Lithuania
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Miller KC, Hughes LE, Long BC, Adams WM, Casa DJ. Validity of Core Temperature Measurements at 3 Rectal Depths During Rest, Exercise, Cold-Water Immersion, and Recovery. J Athl Train 2017; 52:332-338. [PMID: 28207294 PMCID: PMC5402531 DOI: 10.4085/1062-6050-52.2.10] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT No evidence-based recommendation exists regarding how far clinicians should insert a rectal thermistor to obtain the most valid estimate of core temperature. Knowing the validity of temperatures at different rectal depths has implications for exertional heat-stroke (EHS) management. OBJECTIVE To determine whether rectal temperature (Trec) taken at 4 cm, 10 cm, or 15 cm from the anal sphincter provides the most valid estimate of core temperature (as determined by esophageal temperature [Teso]) during similar stressors an athlete with EHS may experience. DESIGN Cross-sectional study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Seventeen individuals (14 men, 3 women: age = 23 ± 2 years, mass = 79.7 ± 12.4 kg, height = 177.8 ± 9.8 cm, body fat = 9.4% ± 4.1%, body surface area = 1.97 ± 0.19 m2). INTERVENTION(S) Rectal temperatures taken at 4 cm, 10 cm, and 15 cm from the anal sphincter were compared with Teso during a 10-minute rest period; exercise until the participant's Teso reached 39.5°C; cold-water immersion (∼10°C) until all temperatures were ≤38°C; and a 30-minute postimmersion recovery period. The Teso and Trec were compared every minute during rest and recovery. Because exercise and cooling times varied, we compared temperatures at 10% intervals of total exercise and cooling durations for these periods. MAIN OUTCOME MEASURE(S) The Teso and Trec were used to calculate bias (ie, the difference in temperatures between sites). RESULTS Rectal depth affected bias (F2,24 = 6.8, P = .008). Bias at 4 cm (0.85°C ± 0.78°C) was higher than at 15 cm (0.65°C ± 0.68°C, P < .05) but not higher than at 10 cm (0.75°C ± 0.76°C, P > .05). Bias varied over time (F2,34 = 79.5, P < .001). Bias during rest (0.42°C ± 0.27°C), exercise (0.23°C ± 0.53°C), and recovery (0.65°C ± 0.35°C) was less than during cooling (1.72°C ± 0.65°C, P < .05). Bias during exercise was less than during postimmersion recovery (0.65°C ± 0.35°C, P < .05). CONCLUSIONS When EHS is suspected, clinicians should insert the flexible rectal thermistor to 15 cm (6 in) because it is the most valid depth. The low level of bias during exercise suggests Trec is valid for diagnosing hyperthermia. Rectal temperature is a better indicator of pelvic organ temperature during cold-water immersion than is Teso.
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Luhring KE, Butts CL, Smith CR, Bonacci JA, Ylanan RC, Ganio MS, McDermott BP. Cooling Effectiveness of a Modified Cold-Water Immersion Method After Exercise-Induced Hyperthermia. J Athl Train 2016; 51:946-951. [PMID: 27874299 DOI: 10.4085/1062-6050-51.12.07] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Recommended treatment for exertional heat stroke includes whole-body cold-water immersion (CWI). However, remote locations or monetary or spatial restrictions can challenge the feasibility of CWI. Thus, the development of a modified, portable CWI method would allow for optimal treatment of exertional heat stroke in the presence of these challenges. OBJECTIVE To determine the cooling rate of modified CWI (tarp-assisted cooling with oscillation [TACO]) after exertional hyperthermia. DESIGN Randomized, crossover controlled trial. SETTING Environmental chamber (temperature = 33.4°C ± 0.8°C, relative humidity = 55.7% ± 1.9%). PATIENTS OR OTHER PARTICIPANTS Sixteen volunteers (9 men, 7 women; age = 26 ± 4.7 years, height = 1.76 ± 0.09 m, mass = 72.5 ± 9.0 kg, body fat = 20.7% ± 7.1%) with no history of compromised thermoregulation. INTERVENTION(S) Participants completed volitional exercise (cycling or treadmill) until they demonstrated a rectal temperature (Tre) ≥39.0°C. After exercise, participants transitioned to a semirecumbent position on a tarp until either Tre reached 38.1°C or 15 minutes had elapsed during the control (no immersion [CON]) or TACO (immersion in 151 L of 2.1°C ± 0.8°C water) treatment. MAIN OUTCOME MEASURE(S) The Tre, heart rate, and blood pressure (reported as mean arterial pressure) were assessed precooling and postcooling. Statistical analyses included repeated-measures analysis of variance with appropriate post hoc t tests and Bonferroni correction. RESULTS Before cooling, the Tre was not different between conditions (CON: 39.27°C ± 0.26°C, TACO: 39.30°C ± 0.39°C; P = .62; effect size = -0.09; 95% confidence interval [CI] = -0.2, 0.1). At postcooling, the Tre was decreased in the TACO (38.10°C ± 0.16°C) compared with the CON condition (38.74°C ± 0.38°C; P < .001; effect size = 2.27; 95% CI = 0.4, 0.9). The rate of cooling was greater during the TACO (0.14 ± 0.06°C/min) than the CON treatment (0.04°C/min ± 0.02°C/min; t15 = -8.84; P < .001; effect size = 2.21; 95% CI = -0.13, -0.08). These differences occurred despite an insignificant increase in fluid consumption during exercise preceding CON (0.26 ± 0.29 L) versus TACO (0.19 ± 0.26 L; t12 = 1.73; P = .11; effect size = 0.48; 95% CI = -0.02, 0.14) treatment. Decreases in heart rate did not differ between the TACO and CON conditions (t15 = -1.81; P = .09; effect size = 0.45; 95% CI = -22, 2). Mean arterial pressure was greater at postcooling with TACO (84.2 ± 6.6 mm Hg) than with CON (67.0 ± 9.0 mm Hg; P < .001; effect size = 2.25; 95% CI = 13, 21). CONCLUSIONS The TACO treatment provided faster cooling than did the CON treatment. When location, monetary, or spatial restrictions are present, TACO represents an effective alternative to traditional CWI in the emergency treatment of patients with exertional hyperthermia.
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Zhang Y, Davis JK, Casa DJ, Bishop PA. Optimizing Cold Water Immersion for Exercise-Induced Hyperthermia: A Meta-analysis. Med Sci Sports Exerc 2016; 47:2464-72. [PMID: 25910052 DOI: 10.1249/mss.0000000000000693] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Cold water immersion (CWI) provides rapid cooling in events of exertional heat stroke. Optimal procedures for CWI in the field are not well established. This meta-analysis aimed to provide structured analysis of the effectiveness of CWI on the cooling rate in healthy adults subjected to exercise-induced hyperthermia. METHODS An electronic search (December 2014) was conducted using the PubMed and Web of Science. The mean difference of the cooling rate between CWI and passive recovery was calculated. Pooled analyses were based on a random-effects model. Sources of heterogeneity were identified through a mixed-effects model Q statistic. Inferential statistics aggregated the CWI cooling rate for extrapolation. RESULTS Nineteen studies qualified for inclusion. Results demonstrate CWI elicited a significant effect: mean difference, 0.03°C·min(-1); 95% confidence interval, 0.03-0.04°C·min(-1). A conservative, observed estimate of the CWI cooling rate was 0.08°C·min(-1) across various conditions. CWI cooled individuals twice as fast as passive recovery. Subgroup analyses revealed that cooling was more effective (Q test P < 0.10) when preimmersion core temperature ≥38.6°C, immersion water temperature ≤10°C, ambient temperature ≥20°C, immersion duration ≤10 min, and using torso plus limbs immersion. There is insufficient evidence of effect using forearms/hands CWI for rapid cooling: mean difference, 0.01°C·min(-1); 95% confidence interval, -0.01°C·min(-1) to 0.04°C·min(-1). A combined data summary, pertaining to 607 subjects from 29 relevant studies, was presented for referencing the weighted cooling rate and recovery time, aiming for practitioners to better plan emergency procedures. CONCLUSIONS An optimal procedure for yielding high cooling rates is proposed. Using prompt vigorous CWI should be encouraged for treating exercise-induced hyperthermia whenever possible, using cold water temperature (approximately 10°C) and maximizing body surface contact (whole-body immersion).
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Affiliation(s)
- Yang Zhang
- 1Chinese Badminton Association, Zhejiang Jiaxing Badminton Association, Zhejiang Province, CHINA; 2Gatorade Sports Science Institute, Barrington, IL; 3Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT; and 4Department of Kinesiology, University of Alabama, Tuscaloosa, AL
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Effects of mild hypohydration on cooling during cold-water immersion following exertional hyperthermia. Eur J Appl Physiol 2016; 116:687-95. [DOI: 10.1007/s00421-016-3329-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/05/2016] [Indexed: 10/22/2022]
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Miller KC, Long BC, Edwards J. Necessity of Removing American Football Uniforms From Humans With Hyperthermia Before Cold-Water Immersion. J Athl Train 2015; 50:1240-6. [PMID: 26678288 DOI: 10.4085/1062-6050-51.1.05] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
CONTEXT The National Athletic Trainers' Association and the American College of Sports Medicine have recommended removing American football uniforms from athletes with exertional heat stroke before cold-water immersion (CWI) based on the assumption that the uniform impedes rectal temperature (T(rec)) cooling. Few experimental data exist to verify or disprove this assumption and the recommendations. OBJECTIVES To compare CWI durations, T(rec) cooling rates, thermal sensation, intensity of environmental symptoms, and onset of shivering when hyperthermic participants wore football uniforms during CWI or removed the uniforms immediately before CWI. DESIGN Crossover study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Eighteen hydrated, physically active men (age = 22 ± 2 years, height = 182.5 ± 6.1 cm, mass = 85.4 ± 13.4 kg, body fat = 11% ± 5%, body surface area = 2.1 ± 0.2 m(2)) volunteered. INTERVENTION(S) On 2 days, participants exercised in the heat (approximately 40°C, approximately 40% relative humidity) while wearing a full American football uniform (shoes; crew socks; undergarments; shorts; game pants; undershirt; shoulder pads; jersey; helmet; and padding over the thighs, knees, hips, and tailbone [PADS]) until T(rec) reached 39.5°C. Next, participants immersed themselves in water that was approximately 10°C while wearing either undergarments, shorts, and crew socks (NOpads) or PADS without shoes until Trec reached 38°C. MAIN OUTCOME MEASURE(S) The CWI duration (minutes) and T(rec) cooling rates (°C/min). RESULTS Participants had similar exercise times (NOpads = 40.8 ± 4.9 minutes, PADS = 43.2 ± 4.1 minutes; t(17) = 2.0, P = .10), hypohydration levels (NOpads = 1.5% ± 0.3%, PADS = 1.6% ± 0.4%; t(17) = 1.3, P = .22), and thermal-sensation ratings (NOpads = 7.2 ± 0.3, PADS = 7.1 ± 0.5; P > .05) before CWI. The CWI duration (median [interquartile range]; NOpads = 6.0 [5.4] minutes, PADS = 7.3 [9.8] minutes; z = 2.3, P = .01) and T(rec) cooling rates (NOpads = 0.28°C/min ± 0.14°C/min, PADS = 0.21°C/min ± 0.11°C/min; t(17) = 2.2, P = .02) differed between uniform conditions. CONCLUSIONS Whereas participants cooled faster in NOpads, we still considered the PADS cooling rate to be acceptable (ie, >0.16°C/min). Therefore, if clinicians experience difficulty removing PADS or CWI treatment is delayed, they may immerse fully equipped hyperthermic football players in CWI and maintain acceptable T(rec) cooling rates. Otherwise, PADS should be removed preimmersion to ensure faster body core temperature cooling.
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Affiliation(s)
- Kevin C Miller
- Schools of *Rehabilitation and Medical Sciences and † Health Sciences, Central Michigan University, Mount Pleasant
| | - Blaine C Long
- Schools of *Rehabilitation and Medical Sciences and † Health Sciences, Central Michigan University, Mount Pleasant
| | - Jeffrey Edwards
- Schools of *Rehabilitation and Medical Sciences and † Health Sciences, Central Michigan University, Mount Pleasant
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Friesen BJ, Carter MR, Poirier MP, Kenny GP. Water immersion in the treatment of exertional hyperthermia: physical determinants. Med Sci Sports Exerc 2015; 46:1727-35. [PMID: 24784433 DOI: 10.1249/mss.0000000000000292] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE We examined the effect of differences in body surface area-to-lean body mass ratio (AD/LBM) on core temperature cooling rates during cold water immersion (CWI, 2°C) and temperate water immersion (TWI, 26°C) after exercise-induced hyperthermia. METHODS Twenty male participants were divided into two groups: high (315.6 ± 7.9 cm·kg, n = 10) and low (275.6 ± 8.6 cm·kg, n = 10) AD/LBM. On two separate occasions, participants ran on a treadmill in the heat (40.0°C, 20% relative humidity) wearing an impermeable rain suit until rectal temperature reached 40.0°C. After exercise, participants were immersed up to the nipples (arms remained out of the water) in either a CWI (2°C) or a TWI (26°C) circulated water bath until rectal temperature returned to 37.5°C. RESULTS Overall rectal cooling rates were significantly different between experimental groups (high vs low AD/LBM, P = 0.005) and between immersion conditions (CWI vs TWI, P < 0.001). Individuals with a high AD/LBM had an approximately 1.7-fold greater overall rectal cooling rate relative to those with low AD/LBM during both CWI (high: 0.27°C·min ± 0.10°C·min vs low: 0.16°C·min ± 0.10°C·min) and TWI (high: 0.10°C·min ± 0.05°C·min vs low: 0.06°C·min ± 0.02°C·min). Further, the overall rectal cooling rates during CWI were approximately 2.7-fold greater than during TWI for both the high (CWI: 0.27°C·min ± 0.10°C·min vs TWI: 0.10°C·min ± 0.05°C·min) and the low (CWI: 0.16°C·min ± 0.10°C·min vs TWI: 0.06°C·min ± 0.02°C·min) AD/LBM groups. CONCLUSION We show that individuals with a low AD/LBM have a reduced rectal cooling rate and take longer to cool than those with a high AD/LBM during both CWI and TWI. However, CWI provides the most effective cooling treatment irrespective of physical differences.
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Affiliation(s)
- Brian J Friesen
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, CANADA
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Carroll JA, Burdick Sanchez NC, Hulbert LE, Ballou MA, Dailey JW, Caldwell LC, Vann RC, Welsh TH, Randel RD. Sexually dimorphic innate immunological responses of pre-pubertal Brahman cattle following an intravenous lipopolysaccharide challenge. Vet Immunol Immunopathol 2015; 166:108-15. [DOI: 10.1016/j.vetimm.2015.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 06/18/2015] [Accepted: 06/20/2015] [Indexed: 11/25/2022]
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Flouris AD, Friesen BJ, Carlson MJ, Casa DJ, Kenny GP. Effectiveness of cold water immersion for treating exertional heat stress when immediate response is not possible. Scand J Med Sci Sports 2015; 25 Suppl 1:229-39. [DOI: 10.1111/sms.12317] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2014] [Indexed: 11/28/2022]
Affiliation(s)
- A. D. Flouris
- FAME Laboratory; Department of Physical Education and Sport Science; University of Thessaly; Trikala Greece
| | - B. J. Friesen
- Human Environmental Physiological Research Unit; University of Ottawa; Ottawa Ontario Canada
| | - M. J. Carlson
- Human Environmental Physiological Research Unit; University of Ottawa; Ottawa Ontario Canada
| | - D. J. Casa
- Korey Stringer Institute; University of Connecticut; Storrs Connecticut USA
| | - G. P. Kenny
- Human Environmental Physiological Research Unit; University of Ottawa; Ottawa Ontario Canada
- Korey Stringer Institute; University of Connecticut; Storrs Connecticut USA
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Raukar NP, Zonfrillo MR, Kane K, Davenport M, Espinoza TR, Weiland J, Franco V, Vaca FE. Gender- and sex-specific sports-related injury research in emergency medicine: a consensus on future research direction and focused application. Acad Emerg Med 2014; 21:1370-9. [PMID: 25420669 DOI: 10.1111/acem.12535] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 07/27/2014] [Accepted: 07/29/2014] [Indexed: 12/13/2022]
Abstract
Title IX, the commercialization of sports, the social change in sports participation, and the response to the obesity epidemic have contributed to the rapid proliferation of participation in both competitive organized sports and nontraditional athletic events. As a consequence, emergency physicians are regularly involved in the acute diagnosis, management, disposition, and counseling of a broad range of sports-related pathology. Three important and highly publicized mechanisms of injury in sports relevant to emergency medicine (EM) include concussion, heat illness, and sudden cardiac death. In conjunction with the 2014 Academic Emergency Medicine consensus conference "Gender-specific Research in Emergency Care: Investigate, Understand, and Translate How Gender Affects Patient Outcomes," a consensus group consisting of experts in EM, emergency neurology, sports medicine, and public health convened to deliberate and develop research questions that could ultimately advance the field of sports medicine and allow for meaningful application in the emergency department (ED) clinical setting. Sex differences in injury risk, diagnosis, ED treatment, and counseling are identified in each of these themes. This article presents the consensus-based priority research agenda.
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Affiliation(s)
- Neha P. Raukar
- Department of Emergency Medicine; Warren Alpert Medical School of Brown University; Providence RI
| | - Mark R. Zonfrillo
- Division of Emergency Medicine and Center for Injury Research and Prevention; Children's Hospital of Philadelphia; Philadelphia PA
| | - Kathleen Kane
- Department of Emergency Medicine; Lehigh Valley Hospital/USF Morsani College of Medicine; Allentown PA
| | - Moira Davenport
- Department of Emergency Medicine; Allegheny General Hospital; Pittsburgh PA
| | | | - Jessica Weiland
- Department of Emergency Medicine; Lehigh Valley Hospital/USF Morsani College of Medicine; Allentown PA
| | - Vanessa Franco
- Department of Emergency Medicine; University of California at Los Angeles; Los Angeles CA
| | - Federico E. Vaca
- Department of Emergency Medicine; Yale University School of Medicine; New Haven CT
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Solianik R, Skurvydas A, Mickevičienė D, Brazaitis M. Intermittent whole-body cold immersion induces similar thermal stress but different motor and cognitive responses between males and females. Cryobiology 2014; 69:323-32. [DOI: 10.1016/j.cryobiol.2014.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 08/20/2014] [Accepted: 08/20/2014] [Indexed: 11/28/2022]
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Treatment of exertional heat stress developed during low or moderate physical work. Eur J Appl Physiol 2014; 114:2551-60. [PMID: 25118838 DOI: 10.1007/s00421-014-2971-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE We examined whether treatment for exertional heat stress via ice water immersion (IWI) or natural recovery is affected by the intensity of physical work performed and, thus, the time taken to reach hyperthermia. METHODS Nine adults (18-45 years; 17.9 ± 2.8 percent body fat; 57.0 ± 2.0 mL kg(-1) min(-1) peak oxygen uptake) completed four conditions incorporating either walking or jogging at 40 °C (20 % relative humidity) while wearing a non-permeable rain poncho. Upon reaching 39.5 °C rectal temperature (Tre), participants recovered either via IWI in 2 °C water or via natural recovery (seated in a ~29 °C environment) until T re returned to 38 °C. RESULTS Cooling rates were greater in the IWI [Tre: 0.24 °C min(-1); esophageal temperature (Tes): 0.24 °C min(-1)] than the natural recovery (Tre and Tes: 0.03 °C min(-1)) conditions (p < 0.001) with no differences between the two moderate and the two low intensity conditions (p > 0.05). Cooling rates for T re and T es were greater in the 39.0-38.5 °C (Tre: 0.19 °C min(-1); Tes: 0.31 °C min(-1)) compared with the 39.5-39.0 °C (Tre: 0.11 °C min(-1); Tes: 0.13 °C min(-1)) period across conditions (p < 0.05). Similar reductions in heart rate and mean arterial pressure were observed during recovery across conditions (p > 0.05), albeit occurred faster during IWI. Percent change in plasma volume at the end of natural recovery and IWI was 5.96 and 9.58%, respectively (p < 0.001). CONCLUSION The intensity of physical work performed and, thus, the time taken to reach hyperthermia does not affect the effectiveness of either IWI treatment or natural recovery. Therefore, while the path to hyperthermia may be different for each patient, the path to recovery must always be immediate IWI treatment.
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Solianik R, Skurvydas A, Vitkauskienė A, Brazaitis M. Gender-specific cold responses induce a similar body-cooling rate but different neuroendocrine and immune responses. Cryobiology 2014; 69:26-33. [DOI: 10.1016/j.cryobiol.2014.04.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/24/2014] [Accepted: 04/24/2014] [Indexed: 12/25/2022]
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Carroll JA, Burdick Sanchez NC, Chaffin R, Chase CC, Coleman SW, Spiers DE. Heat-tolerant versus heat-sensitive Bos taurus cattle: influence of air temperature and breed on the acute phase response to a provocative immune challenge. Domest Anim Endocrinol 2013; 45:163-9. [PMID: 24050374 DOI: 10.1016/j.domaniend.2013.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 08/12/2013] [Accepted: 08/12/2013] [Indexed: 11/25/2022]
Abstract
The difference in the acute phase response of a heat-tolerant and a heat-sensitive Bos taurus breed to a lipopolysaccharide (LPS) challenge when housed at different air temperatures (Ta) was studied. Angus (ANG; heat-sensitive; n = 11; 306 ± 26 kg BW) and Romosinuano (RO; heat-tolerant; n = 10; 313 ± 32 kg BW) heifers were transported from the USDA Agricultural Research Service SubTropical Agricultural Research Station in Florida to the Brody Environmental Chambers at the University of Missouri, Columbia. Heifers were housed in stanchions in 4 temperature-controlled environmental chambers. Initially, Ta in the 4 chambers was cycling at thermoneutrality (TN; 18.5°C-23.5°C) for a 1-wk adjustment period, followed by an increase in 2 of the 4 chambers to cycling heat stress (HS; 24°C-38°C) for 2 wk. On day 19, heifers were fitted with jugular catheters and rectal temperature (RT) recording devices. On day 20, heifers were challenged with LPS (0.5 μg/kg BW; 0 h), sickness behavior scores (SBSs) were recorded, and blood samples were collected at 0.5-h intervals from -2 to 8 h and again at 24 h relative to LPS challenge at 0 h. Serum was isolated and stored at -80°C until analyzed for cortisol and cytokine concentrations. A breed by Ta interaction (P < 0.001) was observed for RT such that the post-LPS average RT in RO heifers housed at TN was lower than the RT of all other treatment groups (P < 0.001), whereas ANG heifers housed at HS had greater post-LPS average RT than all other treatment groups (P < 0.001). In response to LPS, HS increased SBS after LPS in RO heifers compared to RO heifers housed at TN (P < 0.001), whereas HS decreased SBS after LPS in ANG heifers compared to ANG heifers housed at TN (P = 0.014). The cortisol response to LPS was greater in TN than in HS heifers (P < 0.01) and was also greater in RO than in ANG heifers (P = 0.03). A breed by Ta interaction (P < 0.01) was observed for tumor necrosis factor-α (TNF-α) concentration such that HS increased post-LPS serum concentrations of TNF-α in ANG heifers compared to ANG heifers housed at TN (P = 0.041), whereas HS decreased post-LPS concentrations of TNF-α in RO heifers compared to RO heifers housed at TN (P = 0.008). A tendency (P < 0.06) was observed for a breed by Ta interaction for IL-6 concentrations such that RO heifers had greater post-LPS concentrations of IL-6 than ANG heifers when housed at HS (P = 0.020). A breed by Ta interaction was observed for interferon-γ (IFN-γ; P < 0.01) concentrations such that HS decreased post-LPS concentrations of IFN-γ in ANG heifers compared to ANG heifers housed at TN (P < 0.001), and HS increased post-LPS concentrations of IFN-γ in RO heifers compared to RO heifers housed at TN (P = 0.017). These data indicate differences in the acute phase response between the heat-tolerant RO and heat-sensitive ANG heifers under different Ta which may aid in elucidating differences in productivity, disease resistance, and longevity among cattle breeds.
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Affiliation(s)
- J A Carroll
- Livestock Issues Research Unit, USDA Agricultural Research Service, Lubbock, TX 79403, USA.
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Casa DJ, Armstrong LE, Kenny GP, O'Connor FG, Huggins RA. Exertional heat stroke: new concepts regarding cause and care. Curr Sports Med Rep 2012; 11:115-23. [PMID: 22580488 DOI: 10.1249/jsr.0b013e31825615cc] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
When athletes, warfighters, and laborers perform intense exercise in the heat, the risk of exertional heat stroke (EHS) is ever present. The recent data regarding the fatalities due to EHS within the confines of organized American sport are not promising: during the past 35 years, the highest number of deaths in a 5-year period occurred from 2005 to 2009. This reminds us that, regardless of the advancements of knowledge in the area of EHS prevention, recognition, and treatment, knowledge has not been translated into practice. This article addresses important issues related to EHS cause and care. We focus on the predisposing factors, errors in care, physiology of cold water immersion, and return-to-play or duty considerations.
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Affiliation(s)
- Douglas J Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, U-1110, Storrs, CT 06269-1110, USA.
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Gagnon D, Lemire BB, Casa DJ, Kenny GP. Cold-water immersion and the treatment of hyperthermia: using 38.6°C as a safe rectal temperature cooling limit. J Athl Train 2011; 45:439-44. [PMID: 20831387 DOI: 10.4085/1062-6050-45.5.439] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Cold-water immersion is recommended for the immediate field treatment of exertional heat stroke. However, concerns exist over potential overcooling of hyperthermic individuals during cold-water immersion. OBJECTIVE To evaluate the recommendation that removing previously hyperthermic individuals from a cold-water bath at a rectal temperature (T(re)) of 38.6°C would attenuate overcooling. DESIGN Controlled laboratory study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS Participants included 6 men and 4 women (age = 22 ± 3 years, height = 172 ± 10 cm, mass = 67.8 ± 10.7 kg, body fat percentage = 17.1% ± 4.5%, maximum oxygen consumption = 59.3 ± 8.7 mL·kg(-1)·min(-1)). INTERVENTION(S) After exercising at an ambient temperature of 40.0°C for 38.5 ± 9.4 minutes, until T(re) reached 39.5°C, participants were immersed in a 2.0°C circulated water bath until T(re) decreased to either 37.5°C or 38.6°C. Subsequently, participants were removed from the water bath and recovered for 20 minutes at an ambient temperature of 25°C. MAIN OUTCOME MEASURE(S) Rectal and esophageal temperatures were measured continuously during the immersion and recovery periods. RESULTS Because of the experimental design, the overall time of immersion was greater during the 37.5°C trial (16.6 ± 5.7 minutes) than the 38.6°C trial (8.8 ± 2.6 minutes) (t(9) = -4.740, P = .001). During the recovery period after cold-water immersion, both rectal (F(1,9) = 50.540, P < .001) and esophageal (F(1,6) = 20.365, P = .007) temperatures remained greater in the 38.6°C trial than in the 37.5°C trial. This was evidenced by low points of 36.47°C ± 0.70°C and 37.19°C ± 0.71°C for rectal temperature (t(9) = 2.975, P = .016) and of 35.67°C ± 1.27°C and 36.72°C ± 0.95°C for esophageal temperature (t(6) = 3.963, P = .007) during the recovery period of the 37.5°C and 38.6°C trials, respectively. CONCLUSIONS Immersion for approximately 9 minutes to a rectal temperature cooling limit of 38.6°C negated any risk associated with overcooling hyperthermic individuals when they were immersed in 2°C water.
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Affiliation(s)
- Daniel Gagnon
- Human and Environmental Physiology Research Unit, University of Ottawa, ON, Canada
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