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Katch RK, Scarneo SE, Adams WM, Armstrong LE, Belval LN, Stamm JM, Casa DJ. Top 10 Research Questions Related to Preventing Sudden Death in Sport and Physical Activity. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2017; 88:251-268. [PMID: 28805553 DOI: 10.1080/02701367.2017.1342201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Participation in organized sport and recreational activities presents an innate risk for serious morbidity and mortality. Although death during sport or physical activity has many causes, advancements in sports medicine and evidence-based standards of care have allowed clinicians to prevent, recognize, and treat potentially fatal injuries more effectively. With the continual progress of research and technology, current standards of care are evolving to enhance patient outcomes. In this article, we provided 10 key questions related to the leading causes and treatment of sudden death in sport and physical activity, where future research will support safer participation for athletes and recreational enthusiasts. The current evidence indicates that most deaths can be avoided when proper strategies are in place to prevent occurrence or provide optimal care.
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Miller KC, Truxton T, Long B. Temperate-Water Immersion as a Treatment for Hyperthermic Humans Wearing American Football Uniforms. J Athl Train 2017; 52:747-752. [PMID: 28715283 DOI: 10.4085/1062-6050-52.5.05] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Cold-water immersion (CWI; 10°C) can effectively reduce body core temperature even if a hyperthermic human is wearing a full American football uniform (PADS) during treatment. Temperate-water immersion (TWI; 21°C) may be an effective alternative to CWI if resources for the latter (eg, ice) are unavailable. OBJECTIVE To measure rectal temperature (Trec) cooling rates, thermal sensation, and Environmental Symptoms Questionnaire (ESQ) scores of participants wearing PADS or shorts, undergarments, and socks (NOpads) before, during, and after TWI. DESIGN Crossover study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Thirteen physically active, unacclimatized men (age = 22 ± 2 years, height = 182.3 ± 5.2 cm, mass = 82.5 ± 13.4 kg, body fat = 10% ± 4%, body surface area = 2.04 ± 0.16 m2). INTERVENTION(S) Participants exercised in the heat (40°C, 50% relative humidity) on 2 days while wearing PADS until Trec reached 39.5°C. Participants then underwent TWI while wearing either NOpads or PADS until Trec reached 38°C. Thermal sensation and ESQ responses were collected at various times before and after exercise. MAIN OUTCOME MEASURE(S) Temperate-water immersion duration (minutes), Trec cooling rates (°C/min), thermal sensation, and ESQ scores. RESULTS Participants had similar exercise times (NOpads = 38.1 ± 8.1 minutes, PADS = 38.1 ± 8.5 minutes), hypohydration levels (NOpads = 1.1% ± 0.2%, PADS = 1.2% ± 0.2%), and thermal sensation ratings (NOpads = 7.1 ± 0.4, PADS = 7.3 ± 0.4) before TWI. Rectal temperature cooling rates were similar between conditions (NOpads = 0.12°C/min ± 0.05°C/min, PADS = 0.13°C/min ± 0.05°C/min; t12 = 0.82, P = .79). Thermal sensation and ESQ scores were unremarkable between conditions over time. CONCLUSIONS Temperate-water immersion produced acceptable (ie, >0.08°C/min), though not ideal, cooling rates regardless of whether PADS or NOpads were worn. If a football uniform is difficult to remove or the patient is noncompliant, clinicians should begin water-immersion treatment with the athlete fully equipped. Clinicians should strive to use CWI to treat severe hyperthermia, but when CWI is not feasible, TWI should be the next treatment option because its cooling rate was higher than the rates of other common modalities (eg, ice packs, fanning).
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Asplund CA, Miller TK, Creswell L, Getzin A, Hunt A, Martinez J, Diehl J, Hiller WD, Berlin P. Triathlon Medical Coverage: A Guide for Medical Directors. Curr Sports Med Rep 2017; 16:280-288. [PMID: 28696992 DOI: 10.1249/jsr.0000000000000382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interest and participation in triathlon has grown rapidly over the past 20 yr and with this growth, there has been an increase in the number of new events. To maximize the safety of participation, triathlons require medical directors to plan and oversee medical care associated with event participation. Provision of proper medical care requires knowledge of staffing requirements, common triathlon medical conditions, impact of course design, communication skill, and a familiarity of administrative requirements. These guidelines serve as a tool for triathlon medical and race directors to improve race safety for athletes.
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Affiliation(s)
- Chad A Asplund
- 1Georgia Southern University, Statesboro, Statesboro, GA; 2Sports Medicine, Carilion Clinic; 3Virginia Tech/Carilion School of Medicine; 4Division of Cardiothoracic Surgery, University of Mississippi Medical Center, Jackson, MS; 5Sports Medicine and Athletic Performance Cayuga Medical Center Ithaca, NY; 6University of Chicago Pritzker School of Medicine/Northshore University Healthcare; 7TriRock San Diego, ITU San Diego World Championships Kaiser Permanente Sports Medicine, San Diego, CA; 8Riverside Methodist Sports Medicine, Columbus, OH; 9 ITU Medical Committee, University of Hawaii Medical School, Honolulu, HI; and 10Ironman Triathlon World Championship
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Charlot K, Faure C, Antoine-Jonville S. Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review. Nutrients 2017; 9:nu9060592. [PMID: 28604591 PMCID: PMC5490571 DOI: 10.3390/nu9060592] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 01/12/2023] Open
Abstract
Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI) and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY), glucagon-like peptide 1 (GLP-1), and pancreatic polypeptide (PP) levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat) and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected.
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Affiliation(s)
- Keyne Charlot
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, BP 73, 91223 Brétigny-sur-Orge, France.
| | - Cécile Faure
- Laboratoire des Adaptations au Climat Tropical, Exercice et Santé, EA3596, Université des Antilles, Pointe-à-Pitre, BP 250, 97157 Pointe-à-Pitre CEDEX, Guadeloupe, France.
| | - Sophie Antoine-Jonville
- Laboratoire des Adaptations au Climat Tropical, Exercice et Santé, EA3596, Université des Antilles, Pointe-à-Pitre, BP 250, 97157 Pointe-à-Pitre CEDEX, Guadeloupe, France.
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Gomm E, Grimaldi R, Galloway R, Sharma S, Simpson W, Cottingham R. Successful out-of-hospital therapy for heatstroke in three marathon runners with a novel core body cooling device: CAERvest(®). Scand J Med Sci Sports 2017; 26:854-5. [PMID: 27354330 DOI: 10.1111/sms.12676] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2016] [Indexed: 11/30/2022]
Affiliation(s)
- E Gomm
- Department of Anaesthesia, Brighton and Sussex Hospitals NHS Trust, Brighton, UK
| | - R Grimaldi
- Department of Anaesthesia, Brighton and Sussex Hospitals NHS Trust, Brighton, UK
| | - R Galloway
- Department of Emergency Medicine, Brighton and Sussex Hospitals NHS Trust, Brighton, UK
| | - S Sharma
- Department of Cardiology, St George's Hospital Foundation NHS Trust, London, UK
| | - W Simpson
- Research and Development, Bodychillz Ltd, The Beehive, Gatwick, UK
| | - R Cottingham
- Research and Development, Bodychillz Ltd, The Beehive, Gatwick, UK.
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106
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Hosokawa Y, Adams WM, Belval LN, Vandermark LW, Casa DJ. Tarp-Assisted Cooling as a Method of Whole-Body Cooling in Hyperthermic Individuals. Ann Emerg Med 2017; 69:347-352. [DOI: 10.1016/j.annemergmed.2016.08.428] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/23/2016] [Accepted: 08/09/2016] [Indexed: 10/20/2022]
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107
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Mok G, DeGroot D, Hathaway NE, Bigley DP, McGuire CS. Exertional Heat Injury: Effects of Adding Cold (4°C) Intravenous Saline to Prehospital Protocol. Curr Sports Med Rep 2017; 16:103-108. [DOI: 10.1249/jsr.0000000000000345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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108
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Tan PMS, Teo EYN, Ali NB, Ang BCH, Iskandar I, Law LYL, Lee JKW. Evaluation of Various Cooling Systems After Exercise-Induced Hyperthermia. J Athl Train 2017; 52:108-116. [PMID: 28156130 DOI: 10.4085/1062-6050-52.1.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Rapid diagnosis and expeditious cooling of individuals with exertional heat stroke is paramount for survival. OBJECTIVE To evaluate the efficacy of various cooling systems after exercise-induced hyperthermia. DESIGN Crossover study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty-two men (age = 24 ± 2 years, height = 1.76 ± 0.07 m, mass = 70.7 ± 9.5 kg) participated. INTERVENTION(S) Each participant completed a treadmill walk until body core temperature reached 39.50°C. The treadmill walk was performed at 5.3 km/h on an 8.5% incline for 50 minutes and then at 5.0 km/h until the end of exercise. Each participant experienced 4 cooling phases in a randomized, repeated-crossover design: (1) no cooling (CON), (2) body-cooling unit (BCU), (3) EMCOOLS Flex.Pad (EC), and (4) ThermoSuit (TS). Cooling continued for 30 minutes or until body core temperature reached 38.00°C, whichever occurred earlier. MAIN OUTCOME MEASURE(S) Body core temperature (obtained via an ingestible telemetric temperature sensor) and heart rate were measured continuously during the exercise and cooling phases. Rating of perceived exertion was monitored every 5 minutes during the exercise phase and thermal sensation every minute during the cooling phase. RESULTS The absolute cooling rate was greatest with TS (0.16°C/min ± 0.06°C/min) followed by EC (0.12°C/min ± 0.04°C/min), BCU (0.09°C/min ± 0.06°C/min), and CON (0.06°C/min ± 0.02°C/min; P < .001). The TS offered a greater cooling rate than all other cooling modalities in this study, whereas EC offered a greater cooling rate than both CON and BCU (P < .0083 for all). Effect-size calculations, however, showed that EC and BCU were not clinically different. CONCLUSION These findings provide objective evidence for selecting the most effective cooling system of those we evaluated for cooling individuals with exercise-induced hyperthermia. Nevertheless, factors other than cooling efficacy need to be considered when selecting an appropriate cooling system.
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Affiliation(s)
- Pearl M S Tan
- Combat Protection and Performance, Defence Medical and Environmental Research Institute, Singapore
| | - Eunice Y N Teo
- Combat Protection and Performance, Defence Medical and Environmental Research Institute, Singapore
| | | | - Bryan C H Ang
- Soldier Performance Centre, Singapore Armed Forces.,National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | | | - Lydia Y L Law
- Combat Protection and Performance, Defence Medical and Environmental Research Institute, Singapore
| | - Jason K W Lee
- Combat Protection and Performance, Defence Medical and Environmental Research Institute, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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109
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O'Connor JP. Simple and effective method to lower body core temperatures of hyperthermic patients. Am J Emerg Med 2017; 35:881-884. [PMID: 28162872 DOI: 10.1016/j.ajem.2017.01.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 10/20/2022] Open
Abstract
Hyperthermia is a potentially life threatening scenario that may occur in patients due to accompanying morbidities, exertion, or exposure to dry and arid environmental conditions. In particular, heat stroke may result from environmental exposure combined with a lack of thermoregulation. Key clinical findings in the diagnosis of heatstroke are (1) a history of heat stress or exposure, (2) a rectal temperature greater than 40 °C, and (3) central nervous system dysfunction (altered mental state, disorientation, stupor, seizures, or coma) (Prendergast and Erickson, 2014 [1]). In these patients, it is important to bring the body's core temperature down to acceptable levels in a short period of time to avoid tissue/organ injury or death (Yoder, 2001; Casa et al., 2007 [2,3]). A number of potential approaches, both non-invasive and invasive, may be used to lower the temperature of these individuals. Non-invasive techniques generally include: evaporative cooling, ice water immersion, whole-body ice packing, strategic ice packing, and convective cooling. Invasive approaches may include gastric lavage or peritoneal lavage (Schraga and Kates [4]). The efficacy of these methods vary and select treatment approaches may be unsuitable for specific individuals (Schraga and Kates [4]). In this work, the effectiveness of radiation cooling of individuals as a stand-alone treatment and comparisons with existing noninvasive techniques are presented.
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Affiliation(s)
- John P O'Connor
- CSA Medical, Inc., 91 Hartwell Avenue, Lexington, MA 02421, USA.
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110
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Figueroa SA, Guanci MM, Blissitt PA, Cahoon WD. Clinical Q & A: Translating Therapeutic Temperature Management from Theory to Practice. Ther Hypothermia Temp Manag 2017; 7:61-64. [PMID: 28117626 DOI: 10.1089/ther.2017.29025.mkb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | - Patricia A Blissitt
- 4 Clinical Faculty, University of Washington School of Nursing , Seattle, Washington
| | - William D Cahoon
- 5 Virginia Commonwealth University School of Pharmacy , Richmond, Virginia
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111
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Sawaya MA, Ramsey AB, Ramsey PW. American black bear thermoregulation at natural and artificial water sources. URSUS 2017. [DOI: 10.2192/ursu-d-16-00010.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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112
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Willmott AGB, Bliss A, Simpson WH, Tocker SM, Cottingham R, Maxwell NS. CAERvest® - a novel endothermic hypothermic device for core temperature cooling: safety and efficacy testing. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2016; 24:118-128. [PMID: 27997307 DOI: 10.1080/10803548.2016.1273640] [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: 01/06/2023]
Abstract
INTRODUCTION Cooling of the body is used to treat hyperthermic individuals with heatstroke or to depress core temperature below normal for neuroprotection. A novel, chemically activated, unpowered cooling device, CAERvest®, was investigated for safety and efficacy. METHODS Eight healthy male participants (body mass 79.9 ± 1.9 kg and body fat percentage 16.1 ± 3.8%) visited the laboratory (20 °C, 40% relative humidity) on four occasions. Following 30-min rest, physiological and perceptual measures were recorded. Participants were then fitted with the CAERvest® proof of concept (PoC) or prototype 1 (P1), 2 (P2) or 3 (P3) for 60 min. Temperature, cardiovascular and perceptual measures were recorded every 5 min. After cooling, the CAERvest® was removed and the torso checked for cold-related injuries. RESULTS Temperature measures significantly (p < 0.05) reduced pre to post in all trials. Larger reductions in core and skin temperatures were observed for PoC (-0.36 ± 0.18 and -1.55 ± 0.97 °C) and P3 (-0.36 ± 0.22 and -2.47 ± 0.82 °C), compared with P1 and P2. No signs of cold-related injury were observed at any stage. CONCLUSION This study demonstrates that the CAERvest® is an effective device for reducing body temperature in healthy normothermic individuals without presence of cold injury. Further research in healthy and clinical populations is warranted.
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Affiliation(s)
- Ashley G B Willmott
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | - Alex Bliss
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | | | | | | | - Neil S Maxwell
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
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113
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Kenny GP, McGinn R. Restoration of thermoregulation after exercise. J Appl Physiol (1985) 2016; 122:933-944. [PMID: 27881668 DOI: 10.1152/japplphysiol.00517.2016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 10/26/2016] [Accepted: 11/16/2016] [Indexed: 11/22/2022] Open
Abstract
Performing exercise, especially in hot conditions, can heat the body, causing significant increases in internal body temperature. To offset this increase, powerful and highly developed autonomic thermoregulatory responses (i.e., skin blood flow and sweating) are activated to enhance whole body heat loss; a response mediated by temperature-sensitive receptors in both the skin and the internal core regions of the body. Independent of thermal control of heat loss, nonthermal factors can have profound consequences on the body's ability to dissipate heat during exercise. These include the activation of the body's sensory receptors (i.e., baroreceptors, metaboreceptors, mechanoreceptors, etc.) as well as phenotypic factors such as age, sex, acclimation, fitness, and chronic diseases (e.g., diabetes). The influence of these factors extends into recovery such that marked impairments in thermoregulatory function occur, leading to prolonged and sustained elevations in body core temperature. Irrespective of the level of hyperthermia, there is a time-dependent suppression of the body's physiological ability to dissipate heat. This delay in the restoration of postexercise thermoregulation has been associated with disturbances in cardiovascular function which manifest most commonly as postexercise hypotension. This review examines the current knowledge regarding the restoration of thermoregulation postexercise. In addition, the factors that are thought to accelerate or delay the return of body core temperature to resting levels are highlighted with a particular emphasis on strategies to manage heat stress in athletic and/or occupational settings.
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Affiliation(s)
- Glen P Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Canada
| | - Ryan McGinn
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Canada
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114
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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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115
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Yeargin S, McKenzie AL, Eberman LE, Kingsley JD, Dziedzicki DJ, Yoder P. Physiological and Perceived Effects of Forearm or Head Cooling During Simulated Firefighting Activity and Rehabilitation. J Athl Train 2016; 51:927-935. [PMID: 28068165 PMCID: PMC5224734 DOI: 10.4085/1062-6050-51.10.09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Cooling devices aim to protect firefighters by attenuating a rise in body temperature. Devices for head cooling (HC) while firefighting and forearm cooling (FC) during rehabilitation (RHB) intervals are commonly marketed, but research regarding their efficacy is limited. OBJECTIVE To investigate the physiological and perceived effects of HC and FC during firefighting drills and RHB. DESIGN Randomized controlled clinical trial. SETTING Firefighter training center. PATIENTS OR OTHER PARTICIPANTS Twenty-seven male career firefighters (age = 39 ± 7 years; height = 169 ± 7 cm; weight = 95.4 ± 16.8 kg). INTERVENTION(S) Firefighters were randomly assigned to 1 condition: HC (n = 9), in which participants completed drills wearing a cold gel pack inside their helmet; FC (n = 8), in which participants sat on a collapsible chair with water-immersion arm troughs during RHB; or control (n = 10), in which participants used no cooling devices. Firefighters completed four 15-minute drills (D1-D4) wearing full bunker gear and breathing apparatus. Participants had a 15-min RHB after D2 (RHB1) and D4 (RHB2). MAIN OUTCOME MEASURE(S) Change (Δ) in gastrointestinal temperature (TGI), heart rate (HR), physiological strain index, and perceived thermal sensation. RESULTS The TGI increased similarly in the HC and control groups, respectively (D1: 0.57°C ± 0.41°C, 0.73°C ± 0.30°C; D2: 0.92°C ± 0.28°C, 0.85°C ± 0.27°C; D3: -0.37°C ± 0.34°C, -0.01°C ± 0.72°C; D4: 0.25°C ± 0.42°C, 0.57°C ± 0.26°C; P > .05). The ΔHR, Δ physiological strain index, and Δ thermal sensation were similar between the HC and control groups during drills (P > .05). The FC group demonstrated a decreased TGI compared with the control group after RHB1 (-1.61°C ± 0.35°C versus -0.23°C ± 0.34°C; P < .001) and RHB2 (-1.40°C ± 0.38°C versus -0.38°C ± 0.24°C; P < .001). The physiological strain index score decreased in the FC group compared with the control group after RHB1 (-7.9 ± 1.3 versus -2.6 ± 1.7; P < .001) and RHB2 (-7.9 ± 1.6 versus -3.6 ± 1.1; P < .001), but no differences between groups were demonstrated for ΔHR or Δ thermal sensation (P > .05). CONCLUSIONS The HC did not attenuate rises in physiological or perceptual variables during firefighting drills. The FC effectively reduced TGI and the physiological strain index score but not HR or thermal sensation during RHB. Clinicians and firefighters should not recommend the use of HC during firefighting but can consider using FC during RHB intervals in the field.
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Affiliation(s)
- Susan Yeargin
- Exercise Science Department, University of South Carolina, Columbia
| | | | - Lindsey E. Eberman
- Department of Applied Medicine and Rehabilitation, Indiana State University, Terre Haute
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Nye EA, Edler JR, Eberman LE, Games KE. Optimizing Cold-Water Immersion for Exercise-Induced Hyperthermia: An Evidence-Based Paper. J Athl Train 2016; 51:500-1. [PMID: 27441949 DOI: 10.4085/1062-6050-51.9.04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
UNLABELLED Reference: Zhang Y, Davis JK, Casa DJ, Bishop PA. Optimizing cold water immersion for exercise-induced hyperthermia: a meta-analysis. Med Sci Sports Exerc. 2015;47(11):2464-2472. Clinical Questions: Do optimal procedures exist for implementing cold-water immersion (CWI) that yields high cooling rates for hyperthermic individuals? DATA SOURCES One reviewer performed a literature search using PubMed and Web of Science. Search phrases were cold water immersion, forearm immersion, ice bath, ice water immersion, immersion, AND cooling. STUDY SELECTION Studies were included based on the following criteria: (1) English language, (2) full-length articles published in peer-reviewed journals, (3) healthy adults subjected to exercise-induced hyperthermia, and (4) reporting of core temperature as 1 outcome measure. A total of 19 studies were analyzed. DATA EXTRACTION Pre-immersion core temperature, immersion water temperature, ambient temperature, immersion duration, and immersion level were coded a priori for extraction. Data originally reported in graphical form were digitally converted to numeric values. Mean differences comparing the cooling rates of CWI with passive recovery, standard deviation of change from baseline core temperature, and within-subjects r were extracted. Two independent reviewers used the Physiotherapy Evidence Database (PEDro) scale to assess the risk of bias. MAIN RESULTS Cold-water immersion increased the cooling rate by 0.03°C/min (95% confidence interval [CI] = 0.03, 0.04°C/min) compared with passive recovery. Cooling rates were more effective when the pre-immersion core temperature was ≥38.6°C (P = .023), immersion water temperature was ≤10°C (P = .036), ambient temperature was ≥20°C (P = .013), or immersion duration was ≤10 minutes (P < .001). Cooling rates for torso and limb immersion (mean difference = 0.04°C/min, 95% CI = 0.03, 0.06°C/min) were higher (P = .028) than those for forearm and hand immersion (mean difference = 0.01°C/min, 95% CI = -0.01, 0.04°C/min). CONCLUSIONS Hyperthermic individuals were cooled twice as fast by CWI as by passive recovery. Therefore, the former method is the preferred choice when treating patients with exertional heat stroke. Water temperature should be <10°C, with the torso and limbs immersed. Insufficient published evidence supports CWI of the forearms and hands.
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Affiliation(s)
- Emma A Nye
- Department of Applied Medicine and Rehabilitation, Sycamore Center for Wellness and Applied Medicine, Indiana State University, Terre Haute
| | - Jessica R Edler
- Department of Applied Medicine and Rehabilitation, Sycamore Center for Wellness and Applied Medicine, Indiana State University, Terre Haute
| | - Lindsey E Eberman
- Department of Applied Medicine and Rehabilitation, Sycamore Center for Wellness and Applied Medicine, Indiana State University, Terre Haute
| | - Kenneth E Games
- Department of Applied Medicine and Rehabilitation, Sycamore Center for Wellness and Applied Medicine, Indiana State University, Terre Haute
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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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Brownlow MA, Dart AJ, Jeffcott LB. Exertional heat illness: a review of the syndrome affecting racing Thoroughbreds in hot and humid climates. Aust Vet J 2016; 94:240-7. [DOI: 10.1111/avj.12454] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 01/28/2016] [Accepted: 03/22/2016] [Indexed: 12/01/2022]
Affiliation(s)
- MA Brownlow
- Barkers Lodge Road; Picton New South Wales Australia
| | - AJ Dart
- Research and Clinical Trials Unit, University Veterinary Teaching Hospital Camden; University of Sydney; 410 Werombi Road Camden New South Wales, 2570 Australia
| | - LB Jeffcott
- Research and Clinical Trials Unit, University Veterinary Teaching Hospital Camden; University of Sydney; 410 Werombi Road Camden New South Wales, 2570 Australia
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Adams EL, Vandermark LW, Pryor JL, Pryor RR, VanScoy RM, Denegar CR, Huggins RA, Casa DJ. Effects of heat acclimation on hand cooling efficacy following exercise in the heat. J Sports Sci 2016; 35:828-834. [PMID: 27268072 DOI: 10.1080/02640414.2016.1192671] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study examined the separate and combined effects of heat acclimation and hand cooling on post-exercise cooling rates following bouts of exercise in the heat. Seventeen non-heat acclimated (NHA) males (mean ± SE; age, 23 ± 1 y; mass, 75.30 ± 2.27 kg; maximal oxygen consumption [VO2 max], 54.1 ± 1.3 ml·kg-1·min-1) completed 2 heat stress tests (HST) when NHA, then 10 days of heat acclimation, then 2 HST once heat acclimated (HA) in an environmental chamber (40°C; 40%RH). HSTs were 2 60-min bouts of treadmill exercise (45% VO2 max; 2% grade) each followed by 10 min of hand cooling (C) or no cooling (NC). Heat acclimation sessions were 90-240 min of treadmill or stationary bike exercise (60-80% VO2 max). Repeated measures ANOVA with Fishers LSD post hoc (α < 0.05) identified differences. When NHA, C (0.020 ± 0.003°C·min-1) had a greater cooling rate than NC (0.013 ± 0.003°C·min-1) (mean difference [95%CI]; 0.007°C [0.001,0.013], P = 0.035). Once HA, C (0.021 ± 0.002°C·min-1) was similar to NC (0.025 ± 0.002°C·min-1) (0.004°C [-0.003,0.011], P = 0.216). Hand cooling when HA (0.021 ± 0.002°C·min-1) was similar to when NHA (0.020 ± 0.003°C·min-1) (P = 0.77). In conclusion, when NHA, C provided greater cooling rates than NC. Once HA, C and NC provided similar cooling rates.
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Affiliation(s)
- Elizabeth L Adams
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA.,b Department of Nutritional Sciences , The Pennsylvania State University , University Park , PA , USA
| | - Lesley W Vandermark
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA
| | - J Luke Pryor
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA.,c Department of Kinesiology , California State University , Fresno , CA , USA
| | - Riana R Pryor
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA.,c Department of Kinesiology , California State University , Fresno , CA , USA
| | - Rachel M VanScoy
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA
| | - Craig R Denegar
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA
| | - Robert A Huggins
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA
| | - Douglas J Casa
- a Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology , University of Connecticut , Storrs , CT , USA
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120
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Hosokawa Y, Adams WM, Stearns RL, Casa DJ. Comparison of Gastrointestinal and Rectal Temperatures During Recovery After a Warm-Weather Road Race. J Athl Train 2016; 51:382-8. [PMID: 27186918 DOI: 10.4085/1062-6050-51.7.02] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT It has been well established that gastrointestinal temperature (TGI) tracks closely with rectal temperature (TREC) during exercise. However, the field use of TGI pills is still being examined, and little is known about how measurements obtained using these devices compare during recovery after exercise in warm weather. OBJECTIVE To compare TGI and TREC in runners who completed an 11.3-km warm-weather road race and determine if runners with higher TGI and TREC present with greater passive cooling rates during recovery. DESIGN Cross-sectional study. SETTING Field. PATIENTS OR OTHER PARTICIPANTS Thirty recreationally active runners (15 men, 15 women; age = 39 ± 11 years, weight = 68.3 ± 11.7 kg, body fat = 19.2% ± 5.0%). MAIN OUTCOME MEASURE(S) The TGI and TREC were obtained immediately after the race and during a 20-minute passive rest at the 2014 Falmouth Road Race (heat index = 26.2°C ± 0.9°C). Temperatures were taken every 2 minutes during passive rest. The main dependent variables were mean bias and limits of agreement for TGI and TREC, using Bland-Altman analysis, and the 20-minute passive cooling rates for TGI and TREC. RESULTS No differences were evident between TGI and TREC throughout passive rest (P = .542). The passive cooling rates for TGI and TREC were 0.046 ± 0.031°C·min(-1) and 0.060 ± 0.036°C·min(-1), respectively. Runners with higher TGI and TREC at the start of cooling had higher cooling rates (R = 0.682, P < .001 and R = 0.54, P = .001, respectively). The mean bias of TGI during the 20-minute passive rest was -0.06°C ± 0.56°C with 95% limits of agreement of ±1.09°C. CONCLUSIONS After participants completed a warm-weather road race, TGI provided a valid measure of body temperature compared with the criterion measure of TREC. Therefore, TGI may be a viable option for monitoring postexercise-induced hyperthermia, if the pill is administered prophylactically.
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Affiliation(s)
- Yuri Hosokawa
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs
| | - William M Adams
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs
| | - Rebecca L Stearns
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs
| | - Douglas J Casa
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs
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Casa DJ, DeMartini JK, Bergeron MF, Csillan D, Eichner ER, Lopez RM, Ferrara MS, Miller KC, O'Connor F, Sawka MN, Yeargin SW. National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses. J Athl Train 2016; 50:986-1000. [PMID: 26381473 DOI: 10.4085/1062-6050-50.9.07] [Citation(s) in RCA: 319] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. BACKGROUND Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment of, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. RECOMMENDATIONS Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.
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Affiliation(s)
| | | | | | | | - E Randy Eichner
- University of Oklahoma Health Sciences Center, Oklahoma City
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Cramer MN, Jay O. Biophysical aspects of human thermoregulation during heat stress. Auton Neurosci 2016; 196:3-13. [DOI: 10.1016/j.autneu.2016.03.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 12/13/2022]
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Cheshire WP. Thermoregulatory disorders and illness related to heat and cold stress. Auton Neurosci 2016; 196:91-104. [DOI: 10.1016/j.autneu.2016.01.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/17/2015] [Accepted: 01/05/2016] [Indexed: 01/22/2023]
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Butts CL, McDermott BP, Buening BJ, Bonacci JA, Ganio MS, Adams JD, Tucker MA, Kavouras SA. Physiologic and Perceptual Responses to Cold-Shower Cooling After Exercise-Induced Hyperthermia. J Athl Train 2016; 51:252-7. [PMID: 26942657 DOI: 10.4085/1062-6050-51.4.01] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Exercise conducted in hot, humid environments increases the risk for exertional heat stroke (EHS). The current recommended treatment of EHS is cold-water immersion; however, limitations may require the use of alternative resources such as a cold shower (CS) or dousing with a hose to cool EHS patients. OBJECTIVE To investigate the cooling effectiveness of a CS after exercise-induced hyperthermia. DESIGN Randomized, crossover controlled study. SETTING Environmental chamber (temperature = 33.4°C ± 2.1°C; relative humidity = 27.1% ± 1.4%). PATIENTS OR OTHER PARTICIPANTS Seventeen participants (10 male, 7 female; height = 1.75 ± 0.07 m, body mass = 70.4 ± 8.7 kg, body surface area = 1.85 ± 0.13 m(2), age range = 19-35 years) volunteered. INTERVENTION(S) On 2 occasions, participants completed matched-intensity volitional exercise on an ergometer or treadmill to elevate rectal temperature to ≥39°C or until participant fatigue prevented continuation (reaching at least 38.5°C). They were then either treated with a CS (20.8°C ± 0.80°C) or seated in the chamber (control [CON] condition) for 15 minutes. MAIN OUTCOME MEASURE(S) Rectal temperature, calculated cooling rate, heart rate, and perceptual measures (thermal sensation and perceived muscle pain). RESULTS The rectal temperature (P = .98), heart rate (P = .85), thermal sensation (P = .69), and muscle pain (P = .31) were not different during exercise for the CS and CON trials (P > .05). Overall, the cooling rate was faster during CS (0.07°C/min ± 0.03°C/min) than during CON (0.04°C/min ± 0.03°C/min; t16 = 2.77, P = .01). Heart-rate changes were greater during CS (45 ± 20 beats per minute) compared with CON (27 ± 10 beats per minute; t16 = 3.32, P = .004). Thermal sensation was reduced to a greater extent with CS than with CON (F3,45 = 41.12, P < .001). CONCLUSIONS Although the CS facilitated cooling rates faster than no treatment, clinicians should continue to advocate for accepted cooling modalities and use CS only if no other validated means of cooling are available.
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Affiliation(s)
| | | | | | | | | | - J D Adams
- University of Arkansas, Fayetteville
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Demartini JK, Casa DJ, Stearns R, Belval L, Crago A, Davis R, Jardine J. Effectiveness of cold water immersion in the treatment of exertional heat stroke at the Falmouth Road Race. Med Sci Sports Exerc 2016; 47:240-5. [PMID: 24983342 DOI: 10.1249/mss.0000000000000409] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to investigate the effectiveness (speed of cooling and survival rates) of cold water immersion (CWI) in the treatment of patients with exertional heat stroke (EHS). Secondly, this study aimed to compare cooling rates on the basis of gender, age, and initial rectal temperature (Tr). METHODS Eighteen years of finish line medical tent patient records were obtained from the exertional heat illness treatment area at the Falmouth Road Race. Study participants included patients with EHS who were treated with CWI in the medical tent. The number of EHS cases was recorded for each year, and incidence was established on the basis of the number of finishers. Overall cooling rate and differences between initial Tr, age, and sex were evaluated. RESULTS A total of 274 cases of EHS was observed over the 18 yr of collected data. A mean of 15.2 ± 13.0 EHS cases per year was recorded, with an overall incidence of 2.13 ± 1.62 EHS cases per 1000 finishers. The average initial Tr was 41.44°C ± 0.63°C, and the average cooling rate for patients with EHS was 0.22°C·min ± 0.11°C·min. CWI resulted in a 100% survival rate for all patients with EHS. No significant interactions between cooling rate and initial Tr (P = 0.778), sex (P = 0.89), or age (P = 0.70) were observed. CONCLUSIONS CWI was found to effectively treat all cases of EHS observed in this study. CWI provided similar treatment outcomes in all patients, with no significant differences noted on the basis of initial Tr, age, or sex. On the basis of the 100% survival rate from EHS in this large cohort, it is recommended that immediate (on site) CWI be implemented for the treatment of EHS.
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Affiliation(s)
- Julie K Demartini
- 1Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT; and 2Falmouth Hospital, Falmouth, MA
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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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Abstract
Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling.
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Affiliation(s)
- Lisa R Leon
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Abderrezak Bouchama
- King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences, Experimental Medicine Department-King Abdulaziz Medical City-Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
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129
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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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Asplund CA, O'Connor FG. Challenging Return to Play Decisions: Heat Stroke, Exertional Rhabdomyolysis, and Exertional Collapse Associated With Sickle Cell Trait. Sports Health 2015; 8:117-25. [PMID: 26896216 PMCID: PMC4789928 DOI: 10.1177/1941738115617453] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Context: Sports medicine providers frequently return athletes to play after sports-related injuries and conditions. Many of these conditions have guidelines or medical evidence to guide the decision-making process. Occasionally, however, sports medicine providers are challenged with complex medical conditions for which there is little evidence-based guidance and physicians are instructed to individualize treatment; included in this group of conditions are exertional heat stroke (EHS), exertional rhabdomyolysis (ER), and exertional collapse associated with sickle cell trait (ECAST). Evidence Acquisition: The MEDLINE (2000-2015) database was searched using the following search terms: exertional heat stroke, exertional rhabdomyolysis, and exertional collapse associated with sickle cell trait. References from consensus statements, review articles, and book chapters were also utilized. Study Design: Clinical review. Level of Evidence: Level 4. Results: These entities are unique in that they may cause organ system damage capable of leading to short- or long-term detriments to physical activity and may not lend to complete recovery, potentially putting the athlete at risk with premature return to play. Conclusion: With a better understanding of the pathophysiology of EHS, ER, and ECAST and the factors associated with recovery, better decisions regarding return to play may be made.
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Affiliation(s)
- Chad A Asplund
- Athletic Medicine, Division of Health Services, Health and Kinesiology, Georgia Southern University, Statesboro, Georgia
| | - Francis G O'Connor
- Military and Emergency Medicine, Consortium for Health and Military Performance, Uniformed Services University of the Health Sciences, Bethesda, Maryland
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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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132
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Diller KR. Heat Transfer in Health and Healing. JOURNAL OF HEAT TRANSFER 2015; 137:1030011-10300112. [PMID: 26424899 PMCID: PMC4462861 DOI: 10.1115/1.4030424] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 04/01/2015] [Indexed: 05/08/2023]
Abstract
Our bodies depend on an exquisitely sensitive and refined temperature control system to maintain a state of health and homeostasis. The exceptionally broad range of physical activities that humans engage in and the diverse array of environmental conditions we face require remarkable strategies and mechanisms for regulating internal and external heat transfer processes. On the occasions for which the body suffers trauma, therapeutic temperature modulation is often the approach of choice for reversing injury and inflammation and launching a cascade of healing. The focus of human thermoregulation is maintenance of the body core temperature within a tight range of values, even as internal rates of energy generation may vary over an order of magnitude, environmental convection, and radiation heat loads may undergo large changes in the absence of any significant personal control, surface insulation may be added or removed, all occurring while the body's internal thermostat follows a diurnal circadian cycle that may be altered by illness and anesthetic agents. An advanced level of understanding of the complex physiological function and control of the human body may be combined with skill in heat transfer analysis and design to develop life-saving and injury-healing medical devices. This paper will describe some of the challenges and conquests the author has experienced related to the practice of heat transfer for maintenance of health and enhancement of healing processes.
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Affiliation(s)
- Kenneth R Diller
- Department of Biomedical Engineering, The University of Texas at Austin , 107 West Dean Keeton Street , BME 4.202A , Austin, TX 78712-1084 e-mail:
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Brearley M, Walker A. Water immersion for post incident cooling of firefighters; a review of practical fire ground cooling modalities. EXTREME PHYSIOLOGY & MEDICINE 2015; 4:15. [PMID: 26425341 PMCID: PMC4588265 DOI: 10.1186/s13728-015-0034-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 09/17/2015] [Indexed: 11/13/2022]
Abstract
Rapidly cooling firefighters post emergency response is likely to increase the operational effectiveness of fire services during prolonged incidents. A variety of techniques have therefore been examined to return firefighters core body temperature to safe levels prior to fire scene re-entry or redeployment. The recommendation of forearm immersion (HFI) in cold water by the National Fire and Protection Association preceded implementation of this active cooling modality by a number of fire services in North America, South East Asia and Australia. The vascularity of the hands and forearms may expedite body heat removal, however, immersion of the torso, pelvis and/or lower body, otherwise known as multi-segment immersion (MSI), exposes a greater proportion of the body surface to water than HFI, potentially increasing the rates of cooling conferred. Therefore, this review sought to establish the efficacy of HFI and MSI to rapidly reduce firefighters core body temperature to safe working levels during rest periods. A total of 38 studies with 55 treatments (43 MSI, 12 HFI) were reviewed. The core body temperature cooling rates conferred by MSI were generally classified as ideal (n = 23) with a range of ~0.01 to 0.35 °C min(-1). In contrast, all HFI treatments resulted in unacceptably slow core body temperature cooling rates (~0.01 to 0.05 °C min(-1)). Based upon the extensive field of research supporting immersion of large body surface areas and comparable logistics of establishing HFI or MSI, it is recommended that fire and rescue management reassess their approach to fireground rehabilitation of responders. Specifically, we question the use of HFI to rapidly lower firefighter core body temperature during rest periods. By utilising MSI to restore firefighter Tc to safe working levels, fire and rescue services would adopt an evidence based approach to maintaining operational capability during arduous, sustained responses. While the optimal MSI protocol will be determined by the specifics of an individual response, maximising the body surface area immersed in circulated water of up to 26 °C for 15 min is likely to return firefighter Tc to safe working levels during rest periods. Utilising cooler water temperatures will expedite Tc cooling and minimise immersion duration.
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Affiliation(s)
- Matt Brearley
- />National Critical Care and Trauma Response Centre, Level 8 Royal Darwin Hospital, Rocklands Drive, Tiwi, NT 0810 Australia
| | - Anthony Walker
- />Discipline of Sports Studies, Faculty of Health, UC Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT 2601 Australia
- />Australian Capital Territory Fire and Rescue, Amberley Avenue, Fairbairn Business Park, Majura, ACT 2609 Australia
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Casa DJ, DeMartini JK, Bergeron MF, Csillan D, Eichner ER, Lopez RM, Ferrara MS, Miller KC, O'Connor F, Sawka MN, Yeargin SW. National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses. J Athl Train 2015. [PMID: 26381473 DOI: 10.4085/1062-6050-50-9-07] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. BACKGROUND Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment of, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. RECOMMENDATIONS Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.
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Affiliation(s)
| | | | | | | | - E Randy Eichner
- University of Oklahoma Health Sciences Center, Oklahoma City
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Lipman GS, Eifling KP, Ellis MA, Gaudio FG, Otten EM, Grissom CK. Wilderness Medical Society practice guidelines for the prevention and treatment of heat-related illness: 2014 update. Wilderness Environ Med 2015; 25:S55-65. [PMID: 25498263 DOI: 10.1016/j.wem.2014.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 11/29/2022]
Abstract
The Wilderness Medical Society (WMS) convened an expert panel to develop a set of evidence-based guidelines for the recognition, prevention, and treatment of heat illness. We present a review of the classifications, pathophysiology, and evidence-based guidelines for planning and preventive measures as well as best practice recommendations for both field and hospital-based therapeutic management of heat illness. These recommendations are graded on the basis of the quality of supporting evidence, and balance between the benefits and risks or burdens for each modality. This is an updated version of the original WMS Practice Guidelines for the Prevention and Treatment of Heat-Related Illness published in Wilderness & Environmental Medicine 2013;24(4):351-361.
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Affiliation(s)
- Grant S Lipman
- Division of Emergency Medicine, Stanford University School of Medicine, Stanford, CA (Dr Lipman).
| | - Kurt P Eifling
- Division of Emergency Medicine, Barnes-Jewish Hospital/Washington University School of Medicine, Saint Louis, MO (Dr Eifling)
| | - Mark A Ellis
- Department of Emergency Medicine, Spartanburg Regional Healthcare System, Spartanburg, SC (Dr Eifling)
| | - Flavio G Gaudio
- Division of Emergency Medicine, New York-Presbyterian Hospital/Weill Cornell Medical College, New York, NY (Dr Gaudio)
| | - Edward M Otten
- Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH (Dr Otten)
| | - Colin K Grissom
- Pulmonary and Critical Care Division, Intermountain Medical Center and the University of Utah, Salt Lake City, UT (Dr Grissom)
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Hoffman MD, Rogers IR, Joslin J, Asplund CA, Roberts WO, Levine BD. Managing collapsed or seriously ill participants of ultra-endurance events in remote environments. Sports Med 2015; 45:201-12. [PMID: 25326844 DOI: 10.1007/s40279-014-0270-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Increasing participation in ultramarathons and other ultra-endurance events amplifies the potential for serious medical issues during and immediately following these competitions. Since these events are often located in remote settings where access may be extremely limited; the diagnostic capabilities, treatment options, and expectations of medical care may differ from those of urban events. This work outlines a process for assessment and treatment of athletes presenting for medical attention in remote environments, with a focus on potentially serious conditions such as major trauma, acute coronary syndrome, exertional heat stroke, hypothermia, hypoglycemia, exercise-associated hyponatremic encephalopathy, severe dehydration, altitude illness, envenomation, anaphylaxis, and bronchospasm. A list of suggested medical supplies is provided and discussed. But, given that diagnostic and treatment options may be extremely limited in remote settings, it is important for medical providers to understand how to assess and manage the most common serious medical issues with limited resources, and to be prepared to make presumptive diagnoses when necessary.
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Affiliation(s)
- Martin D Hoffman
- Department of Physical Medicine and Rehabilitation, University of California Davis Medical Center, Sacramento, CA, USA,
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Stewart TE, Whitford AC. Dangers of Prehospital Cooling: A Case Report of Afterdrop in a Patient with Exertional Heat Stroke. J Emerg Med 2015; 49:630-3. [PMID: 26289615 DOI: 10.1016/j.jemermed.2015.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/01/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Exertional heat stroke is a potentially life-threatening disease with varying clinical presentations and severity. Given the severe morbidity that can accompany the disease, the immediate management often begins in the prehospital setting. It is important to have not only a comprehensive understanding of the prehospital cooling methods in addition to hospital management strategies, but an understanding of their potential complications as well. CASE REPORT A 32-year-old male presented to a San Antonio hospital in March 2014 with progressive confusion, nausea, nonbloody emesis, and ataxia. Initial presentation was concerning for exertional heat stroke, as the patient was recorded in the field to have a temperature of 42.1°C (106.2°F). The patient, on arrival to the emergency department, was found to have a core body temperature of 38.1°C (100.6°F). All active cooling measures were terminated and active rewarming was initiated. Despite adequate resuscitation and rapid identification of the patient's overcorrection in core body temperature, the lowest recorded temperature was 36.0°C (96.8°F). Why Should an Emergency Physician Be Aware of This? This case represents the dangers associated with exertional heat stroke, overcorrection of core body temperature, and the potentially lethal complication of afterdrop. It also represents the need for immediate recognition of the condition and initiation of appropriate medical care. Although this patient's clinical outcome was good, the event could have caused serious morbidity or could have potentially been fatal.
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Affiliation(s)
- Todd E Stewart
- Department of Emergency Medicine, University of Texas Health Science Center San Antonio, San Antonio, Texas
| | - Allen C Whitford
- Department of Emergency Medicine, University of Texas Health Science Center San Antonio, San Antonio, Texas
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138
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Miller KC, Swartz EE, Long BC. Cold-Water Immersion for Hyperthermic Humans Wearing American Football Uniforms. J Athl Train 2015; 50:792-9. [PMID: 26090706 PMCID: PMC4629934 DOI: 10.4085/1062-6050-50.6.01] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Current treatment recommendations for American football players with exertional heatstroke are to remove clothing and equipment and immerse the body in cold water. It is unknown if wearing a full American football uniform during cold-water immersion (CWI) impairs rectal temperature (Trec) cooling or exacerbates hypothermic afterdrop. OBJECTIVE To determine the time to cool Trec from 39.5°C to 38.0°C while participants wore a full American football uniform or control uniform during CWI and to determine the uniform's effect on Trec recovery postimmersion. DESIGN Crossover study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 18 hydrated, physically active, unacclimated men (age = 22 ± 3 years, height = 178.8 ± 6.8 cm, mass = 82.3 ± 12.6 kg, body fat = 13% ± 4%, body surface area = 2.0 ± 0.2 m(2)). INTERVENTION(S) Participants wore the control uniform (undergarments, shorts, crew socks, tennis shoes) or full uniform (control plus T-shirt; tennis shoes; jersey; game pants; padding over knees, thighs, and tailbone; helmet; and shoulder pads). They exercised (temperature approximately 40°C, relative humidity approximately 35%) until Trec reached 39.5°C. They removed their T-shirts and shoes and were then immersed in water (approximately 10°C) while wearing each uniform configuration; time to cool Trec to 38.0°C (in minutes) was recorded. We measured Trec (°C) every 5 minutes for 30 minutes after immersion. MAIN OUTCOME MEASURE(S) Time to cool from 39.5°C to 38.0°C and Trec. RESULTS The Trec cooled to 38.0°C in 6.19 ± 2.02 minutes in full uniform and 8.49 ± 4.78 minutes in control uniform (t17 = -2.1, P = .03; effect size = 0.48) corresponding to cooling rates of 0.28°C·min(-1) ± 0.12°C·min(-1) in full uniform and 0.23°C·min(-1) ± 0.11°C·min(-1) in control uniform (t17 = 1.6, P = .07, effect size = 0.44). The Trec postimmersion recovery did not differ between conditions over time (F1,17 = 0.6, P = .59). CONCLUSIONS We speculate that higher skin temperatures before CWI, less shivering, and greater conductive cooling explained the faster cooling in full uniform. Cooling rates were considered ideal when the full uniform was worn during CWI, and wearing the full uniform did not cause a greater postimmersion hypothermic afterdrop. Clinicians may immerse football athletes with hyperthermia wearing a full uniform without concern for negatively affecting body-core cooling.
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Affiliation(s)
- Kevin C. Miller
- School of Rehabilitation and Medical Sciences, Central Michigan University, Mount Pleasant
| | - Erik E. Swartz
- Department of Kinesiology, University of New Hampshire, Durham
| | - Blaine C. Long
- School of Rehabilitation and Medical Sciences, Central Michigan University, Mount Pleasant
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EFFECT OF ACTIVE COOLING AND α-2 ADRENOCEPTOR ANTAGONISM ON CORE TEMPERATURE IN ANESTHETIZED BROWN BEARS (URSUS ARCTOS). J Zoo Wildl Med 2015; 46:279-85. [PMID: 26056880 DOI: 10.1638/2014-0052r.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hyperthermia is a common complication during anesthesia of bears, and it can be life threatening. The objective of this study was to evaluate the effectiveness of active cooling on core body temperature for treatment of hyperthermia in anesthetized brown bears (Ursus arctos). In addition, body temperature after reversal with atipamezole was also evaluated. Twenty-five adult and subadult brown bears were captured with a combination of zolazepam-tiletamine and xylazine or medetomidine. A core temperature capsule was inserted into the bears' stomach or 15 cm into their rectum or a combination of both. In six bears with gastric temperatures≥40.0°C, an active cooling protocol was performed, and the temperature change over 30 min was analyzed. The cooling protocol consisted of enemas with 2 L of water at approximately 5°C/100 kg of body weight every 10 min, 1 L of intravenous fluids at ambient temperature, water or snow on the paws or the inguinal area, intranasal oxygen supplementation, and removing the bear from direct sunlight or providing shade. Nine bears with body temperature>39.0°C that were not cooled served as control for the treated animals. Their body temperatures were recorded for 30 min, prior to administration of reversal. At the end of the anesthetic procedure, all bears received an intramuscular dose of atipamezole. In 10 bears, deep rectal temperature change over 30 min after administration of atipamezole was evaluated. The active cooling protocol used in hyperthermic bears significantly decreased their body temperatures within 10 min, and it produced a significantly greater decrease in their temperature than that recorded in the control group.
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141
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Lissoway JB, Lipman GS, Grahn DA, Cao VH, Shaheen M, Phan S, Weiss EA, Heller HC. Novel Application of Chemical Cold Packs for Treatment of Exercise-Induced Hyperthermia: A Randomized Controlled Trial. Wilderness Environ Med 2015; 26:173-9. [DOI: 10.1016/j.wem.2014.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/27/2014] [Accepted: 11/17/2014] [Indexed: 10/23/2022]
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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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Abstract
AbstractExertional heat illness is a classification of disease with clinical presentations that are not always diagnosed easily. Exertional heat stroke is a significant cause of death in competitive sports, and the increasing popularity of marathons races and ultra-endurance competitions will make treating many heat illnesses more common for Emergency Medical Services (EMS) providers. Although evidence is available primarily from case series and healthy volunteer studies, the consensus for treating exertional heat illness, coupled with altered mental status, is whole body rapid cooling. Cold or ice water immersion remains the most effective treatment to achieve this goal. External thermometry is unreliable in the context of heat stress and direct internal temperature measurement by rectal or esophageal probes must be used when diagnosing heat illness and during cooling. With rapid recognition and implementation of effective cooling, most patients suffering from exertional heat stroke will recover quickly and can be discharged home with instructions to rest and to avoid heat stress and exercise for a minimum of 48 hours; although, further research pertaining to return to activity is warranted.PryorRR,RothRN,SuyamaJ,HostlerD.Exertional heat illness: emerging concepts and advances in prehospital care.Prehosp Disaster Med.2015;30(3):19.
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Walker A, Argus C, Driller M, Rattray B. Repeat work bouts increase thermal strain for Australian firefighters working in the heat. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2015; 21:285-93. [PMID: 25849044 DOI: 10.1179/2049396715y.0000000006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
BACKGROUND Firefighters regularly re-enter fire scenes during long duration emergency events with limited rest between work bouts. It is unclear whether this practice is impacting on the safety of firefighters. OBJECTIVES To evaluate the effects of multiple work bouts on firefighter physiology, strength, and cognitive performance when working in the heat. METHODS Seventy-seven urban firefighters completed two 20-minute simulated search and rescue tasks in a heat chamber (105 ± 5°C), separated by a 10-minute passive recovery. Core and skin temperature, rate of perceived exertion (RPE), thermal sensation (TS), grip strength, and cognitive changes between simulations were evaluated. RESULTS Significant increases in core temperature and perceptual responses along with declines in strength were observed following the second simulation. No differences for other measures were observed. CONCLUSIONS A significant increase in thermal strain was observed when firefighters re-entered a hot working environment. We recommend that longer recovery periods or active cooling methods be employed prior to re-entry.
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Affiliation(s)
- Anthony Walker
- Discipline of Sport and Exercise Science, UC Research Institute for Sport and Exercise, University of Canberra, ACT , Australia
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Sloan BK, Kraft EM, Clark D, Schmeissing SW, Byrne BC, Rusyniak DE. On-site treatment of exertional heat stroke. Am J Sports Med 2015; 43:823-9. [PMID: 25632055 DOI: 10.1177/0363546514566194] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Exertional heat stroke is a devastating condition that can cause significant morbidity and mortality. Rapid cooling is the most effective means of treating heat stroke, but little is published on the safety and logistics of cooling patients on site at a major sporting event. PURPOSE To describe an on-site exertional heat stroke treatment protocol and to compare the outcomes of patients treated on site to those transferred to hospitals. STUDY DESIGN Descriptive epidemiological study. METHODS Using race-day medical records and ambulance run sheets, patients who developed exertional heat stroke at the Indianapolis half-marathon from 2005 to 2012 were identified. Exertional heat stroke was defined as runners with a core temperature measured with a rectal thermometer greater than 102° F and altered mental status. Clinical information and patient outcomes were abstracted from the race medical tent and hospital charts by 3 separate trained reviewers using structured methods and a data collection form. Two reviewers, using a RedCAP database and dual-data entry, abstracted records for each patient. A third arbitrated all discrepancies between reviewers. Clinical signs, treatments, and outcomes were calculated using descriptive statistics, and data were grouped and compared for patients treated on site or transferred to local hospitals for treatment. RESULTS Over 235,000 athletes participated in the event over the 8-year period, with 696 seeking medical care. A total of 32 heat stroke victims were identified during the study period; of these, 22 were treated on site. Of these, 68% were treated with cold-water immersion and 59% were discharged home from the race. Ten exertional heat stroke patients were transported from the race course to local hospitals. None of them underwent cold-water immersion, and 40% of them were subsequently discharged home. No patients in the study died. CONCLUSION On-site treatment of athletes who develop exertional heat stroke appears to be both safe and effective. On-site treatment may decrease the local burden of critically ill patients to emergency departments during large athletic events.
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Affiliation(s)
- Brian K Sloan
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Emily M Kraft
- Department of Emergency Medicine, Western Michigan University, Kalamazoo, Michigan, USA
| | - Dave Clark
- Methodist Hospital, Manager of Emergency Medical Services, Indianapolis, Indiana, USA
| | - Scott W Schmeissing
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Brian C Byrne
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Daniel E Rusyniak
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Rattray B, Argus C, Martin K, Northey J, Driller M. Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance? Front Physiol 2015; 6:79. [PMID: 25852568 PMCID: PMC4362407 DOI: 10.3389/fphys.2015.00079] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/27/2015] [Indexed: 11/23/2022] Open
Abstract
Key PointsCentral fatigue is accepted as a contributor to overall athletic performance, yet little research directly investigates post-exercise recovery strategies targeting the brain Current post-exercise recovery strategies likely impact on the brain through a range of mechanisms, but improvements to these strategies is needed Research is required to optimize post-exercise recovery with a focus on the brain
Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimizing recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilized recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimizing brain fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.
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Affiliation(s)
- Ben Rattray
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Christos Argus
- University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Kristy Martin
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Joseph Northey
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Matthew Driller
- Department of Sport and Leisure Studies, The University of Waikato Hamilton, New Zealand
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Cheung SS. Responses of the hands and feet to cold exposure. Temperature (Austin) 2015; 2:105-20. [PMID: 27227009 PMCID: PMC4843861 DOI: 10.1080/23328940.2015.1008890] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 11/19/2022] Open
Abstract
An initial response to whole-body or local exposure of the extremities to cold is a strong vasoconstriction, leading to a rapid decrease in hand and foot temperature. This impairs tactile sensitivity, manual dexterity, and muscle contractile characteristics while increasing pain and sympathetic drive, decreasing gross motor function, occupational performance, and survival. A paradoxical and cyclical vasodilatation often occurs in the fingers, toes, and face, and this has been termed the hunting response or cold-induced vasodilatation (CIVD). Despite being described almost a century ago, the mechanisms of CIVD are still disputed; research in this area has remained largely descriptive in nature. Recent research into CIVD has brought increased standardization of methodology along with new knowledge about the impact of mediating factors such as hypoxia and physical fitness. Increasing mechanistic analysis of CIVD has also emerged along with improved modeling and prediction of CIVD responses. The present review will survey work conducted during this century on CIVD, its potential mechanisms and modeling, and also the broader context of manual function in cold conditions.
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Affiliation(s)
- Stephen S Cheung
- Environmental Ergonomics Laboratory; Department of Kinesiology ; Brock University; St. Catharines , Canada
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148
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Affiliation(s)
- Grant S Lipman
- Division of Emergency Medicine, Department of Surgery, Stanford University School of Medicine, 300 Pasteur Drive, Alway Building, M121, Redwood City, CA, 94305, USA,
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149
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Abstract
Exertional heat-related illness (EHRI) is comprised of several states that afflict physically active persons when exercising during conditions of high environmental heat stress. Certain forms of EHRI may become life threatening if not treated. Exertional heat stroke (EHS), characterized by a core body temperature of >40 ° C and mental status changes, is the most severe form of EHRI. EHS must be treated immediately with rapid body cooling to reduce morbidity and mortality. Many EHRI cases are preventable by following heat acclimatization guidelines, modifying sports and exercise sessions during conditions of high environmental heat stress, maintaining adequate hydration, avoiding exertion in the heat when ill, and by educating sports medicine personnel, coaches, parents, and athletes on the early recognition and prevention of EHRI. Heat exhaustion, exercise-associated collapse, exercise-associated muscle cramps, exercise-associated hyponatremia, and exertional rhabdomyolysis are also described.
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Affiliation(s)
- Andrew W Nichols
- Family Medicine and Community Health, John A. Burns School of Medicine, University of Hawaii at Mānoa, University Health Services Mānoa, 1710 East-West Road, Honolulu, HI, 96822, USA,
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150
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Savage RJ, Lord C, Larsen BL, Knight TL, Langridge PD, Aisbett B. Firefighter feedback during active cooling: A useful tool for heat stress management? J Therm Biol 2014; 46:65-71. [DOI: 10.1016/j.jtherbio.2014.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/10/2014] [Accepted: 10/10/2014] [Indexed: 01/01/2023]
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