Exertional Heat Illness Prevention Research Articles

Association between the experience of exertional heat illness (EHI) and living conditions of collegiate student athletes.

Exertional heatstroke (EHS), a severe form of exertional heat illness (EHI), is the third leading cause of death in athletes; thus, early detection and prevention of EHI can help prevent EHS, which is a life-threatening condition. This study aimed to clarify the association between the cognizance of experiencing EHI and living conditions and specific EHI symptoms among collegiate athletes. This study was conducted in October 2022 by administering a questionnaire to 237 male collegiate athletes. Of the 215 (90.7%) respondents, 197 (91.6%) provided valid responses; among them, 88 (44.7%) responded they had experienced EHI, while 109 (55.3%) had not. A history of medical examinations due to EHI, having experienced headaches during summer activities, and having read the EHI manual were factors indicating cognizance of EHI. The number of times meals containing a staple food, main dish, and side dish were eaten in a day was a factor in preventing EHI. Early detection of EHI is important for its prevention, and it is important that athletes themselves have knowledge of symptoms and can correctly self-diagnose EHI. Emphasizing the potential of a well-balanced dietary intake has the potential to prevent EHI is crucial.

Exertional Heat Illness Prevention

Exertional Heat Illness Prevention

Exertional Heat Illness: Adoption of Policies and Influencing Contextual Factors as Reported by Athletic Administrators.

Little is known about the adoption by athletic administrators (AAs) of exertional heat illness (EHI) policies, and the corresponding facilitators and barriers of such policies within high school athletics. This study describes the adoption of comprehensive EHI policies by high school AAs and explores factors influencing EHI policy adoption. We hypothesized that <50% of AAs would report adoption of an EHI policy, and that the most common facilitator would be access to an athletic trainer (AT), whereas the most common barrier would be financial limitations. Cross-sectional. Level 4. A total of 466 AAs (82.4% male; age, 48 ± 9 years) completed a validated online survey to assess EHI prevention and treatment policy adoption (11 components), as well as facilitators and barriers to policy implementation. Access to athletic training services was ascertained by matching the participants' zip codes with the Athletic Training Locations and Services Project. Policy adoption, facilitators, and barriers data are presented as summary statistics (proportions, interquartile range (IQR)). A Welch t test evaluated the association between access to athletic training services and EHI policy adoption. Of the AAs surveyed, 77.9% (n = 363) reported adopting a written EHI policy. The median of EHI policy components adopted was 5 (IQR = 1,7), with only 5.6% (n = 26) of AAs reporting adoption of all policy components. AAs who had access to an AT (P = 0.04) were more likely to adopt a greater number of EHI-related policies, compared with those without access to an AT. An AT employed at the school was the most frequently reported facilitator (36.9%). Most AAs reported having written EHI policy components, and access to an AT resulted in a more comprehensive policy. Employment of an AT within high school athletics may serve as a vital component in facilitating the adoption of comprehensive EHI policies.

Prevention of exertional heat illness among high school baseball athletes and coaches : knowledge, attitude, practice, facilitators, and barriers

Prevention of exertional heat illness among high school baseball athletes and coaches : knowledge, attitude, practice, facilitators, and barriers

An investigation into environmental variables influencing post-race exertional heat illness in thoroughbred racehorses in temperate eastern Australia.

Exertional heat illness (EHI) is a syndrome that occurs when metabolic heat production from muscular contraction exceeds the rate at which it can be dissipated. Core body temperature rises to critical levels, causing hyperthermia and central nervous system dysfunction. Best practice for the prevention of EHI centres around early detection, rapid response and aggressive cooling. Advance planning enables risk mitigation measures. The more that is known about EHI in horses, the better prepared those in the positions of responsibility can be to anticipate events in which the risk of EHI may be elevated. This prospective, observational study investigated environmental risk factors associated with the occurrence of EHI. From 2014 to 2018, the number of horses exhibiting the symptoms of post-race EHI was recorded at 73 convenience sampled race meetings. Of the 4809 starters, the signs of EHI were recorded for 457. Thermal environmental data were measured and included ambient temperature, radiant heat, vapor pressure (humidity) and wind speed (WS). Mixed linear regression models were computed to assess the associations between the occurrence and incidence of post-race EHI and the four thermal environmental variables. The analysis showed that vapor pressure and WS had the largest effects on the occurrence of post-race EHI. The major limitations were that the race meetings selected were convenience sampled according to attendance by the first author and individual horse data were not available. EHI is influenced by a complex interaction of independently acting environmental variables, but warm, windless, humid days are most likely to result in the cases of EHI.

Collegiate Marching Band Artists Experience High Core Body Temperatures during Rehearsals and Performances.

No research has investigated thermoregulatory responses and exertional heat illness (EHI) risk factors in marching band (MB) artists performing physical activity in high environmental temperatures. Examine core temperature (Tc) and EHI risk factors in MB artists. Descriptive epidemiology study. Three rehearsals and 2 football games for 2 NCAA Division I MBs. Nineteen volunteers completed the study (female = 13, males = 6; age = 20.5 ± 0.9 years; weight = 75.0 ± 19.1 kg; height = 165.1 ± 7.1 cm). We measured Tc pre-, post-, and every 15 minutes during activity and recorded wet-bulb globe temperature (WBGT) and relative humidity (RH) every 15 minutes. Other variables included activity time and intensity, ground surface, hydration characteristics (fluid volume, sweat rate, urine specific gravity, percent body mass loss [%BM]), and medical history (eg, previous EHI, medications). Statistical analysis included descriptives (mean ± standard deviation), comparative analyses determined differences within and between days, and linear regression identified variables that significantly explained Tc. Mean rehearsal time = 102.8 ± 19.8 minutes and game time = 260.5 ± 47.7 minutes. Max game Tc (39.1 ± 1.1°C) was significantly higher than rehearsal (38.4 ± 0.7°C, P = .003). The highest max game Tc = 41.2°C. Participants consumed significantly more fluid than their sweat rates (P < .003), which minimized %BM loss, particularly during rehearsals (-0.4 ± 0.6%). Mean game %BM loss = -0.9 ± 2.0%; however, 63.6% of the time, participants reported hypohydrated to game day. Max Tc was significantly predicted by max WBGT, max RH, ground surface, using mental health medications, and hours of sleep (adjusted R2 = 0.542, P < .001). Marching band artists experience high Tc during activity and should have access to athletic trainers who can implement EHI prevention and management strategies.

The Epidemiology and Management of Exertional Heat Illnesses in High School Sports During the 2012/2013–2016/2017 Academic Years.

Context: Recent data on exertional heat illness (EHI) in high school sports are limited yet warranted to identify specific settings with the highest risk of EHI. Objective: To describe the epidemiology of EHI in high school sports during the 2012/2013-2016/2017 academic years. Design: Descriptive epidemiology study. Setting: Aggregate injury and exposure data collected from athletic trainers working in high school sports in the United States. Patients or Other Participants: High school athletes during the 2012/2013-2016/2017 academic years. Intervention: High School Reporting Information Online surveillance system data from the 2012/2013-2016/2017 academic years were analyzed. Main Outcome Measures: EHI counts, rates per 10,000 athlete exposures (AEs), and distributions were examined by sport, event type, and US census region. EHI management strategies provided by athletic trainers were analyzed. Injury rate ratios with 95% confidence intervals (CIs) compared EHI rates. Results: Overall, 300 EHIs were reported for an overall rate of 0.13/10,000 AE (95% CI, 0.11 to 0.14). Of these, 44.3% occurred in American football preseason practices; 20.7% occurred in American football preseason practices with a registered air temperature ≥90°F and ≥1 hour into practice. The EHI rate was higher in American football than all other sports (0.52 vs 0.04/10,000 AE; injury rate ratio = 11.87; 95% CI, 9.22 to 15.27). However, girls' cross-country had the highest competition EHI rate (1.18/10,000 AE). The EHI rate was higher in the South US census region than all other US census regions (0.23 vs 0.08/10,000 AE; injury rate ratio = 2.96; 95% CI, 2.35 to 3.74). Common EHI management strategies included having medical staff on-site at the onset of EHI (92.7%), removing athlete from play (85.0%), and giving athlete fluids via the mouth (77.7%). Conclusions: American football continues to have the highest overall EHI rate although the high competition EHI rate in girls' cross-country merits additional examination. Regional differences in EHI incidence, coupled with sport-specific variations in management, may highlight the need for region- and sport-specific EHI prevention guidelines.

Sports Medicine Staff Size Influences Exertional Heat Illness Policies in High School Football

All high schools should implement exertional heat illness (EHI) safety strategies. We determined if there were differences in the implementation of EHI safety strategies between schools with and without additional paid athletic trainers (ATs) or a team physician present at preseason football practices. High schools with multiple ATs or a team physician implemented more EHI prevention and management strategies than schools with only a single AT, including training staff in EHI recognition and treatment and having an emergency action plan. However, schools with a paid team physician were more likely to have double practices in the first week of football practice. Schools with additional medical personnel at football preseason practices were more likely to implement EHI safety strategies.

Probability of Heat Intolerance: Standardized Interpretation of Heat-Tolerance Testing Results Versus Specialist Judgment.

The heat-tolerance test (HTT) is a screening tool for secondary prevention of exertional heat illness by the Israel Defense Forces. To discern participant tolerance, recruits are exposed to intermediate environmental and exercise stresses, and their physiological responses, core temperature, and heart rate are monitored. When their physiological measures rise at a higher rate or exceed the upper levels of absolute values compared with other participants, heat intolerance (HI) is diagnosed. To develop a mathematical model to interpret HTT results and provide a quantitative estimate of the probability of heat tolerance (PHT). Cross-sectional study. Warrior Health Research Institute. The HTT results of 175 random individuals tested after an episode of exertional heat illness were classified qualitatively and then divided into training (n = 112) and testing (n = 63) datasets. All individuals were male soldiers (age range = 18-22 years) who had sustained an episode of definitive or suspected exertional heat stroke. Based on the decision algorithm used by the Israel Defense Forces for manual interpretation of the HTT, we designed a logistic regression model to predict the heat-tolerance state. The model used a time series of physiological measures (core temperature and heart rate) of individuals to predict the manually assigned diagnosis of HT or HI. It was initially fitted and then tested on 2 separate, random datasets. The model produced a single value, the PHT, and its predictive ability was demonstrated by prediction-density plots, receiver operating characteristic curve, contingency tables, and conventional screening test evaluation measures. According to prediction-density plots of the testing set, all HT patients had a PHT of 0.7 to 1. The receiver operating characteristic curve plot showed that PHT was an excellent predictor of the manual HT interpretations (area under the curve = 0.973). Using a cutoff probability of 0.5 for the diagnosis of HI, we found that PHT had sensitivity, specificity, and accuracy of 100%, 90%, and 92.06%, respectively. The PHT has the potential to be substituted for manual interpretation of the HTT and to serve in a variety of clinical and research applications.

The validity of the heat tolerance test in prediction of recurrent exertional heat illness events

ObjectivesHeat-tolerance-testing (HTT) protocol is used as a screening test for secondary prevention of exertional heat illness (EHI) in the military. Subjects whose test results are positive (heat-intolerant, HI) are presumed to be at higher risk of repeated EHI events than heat-tolerant subjects (HT) and are therefore prevented from return to combat duty, but may return to unsupervised recreational activity. Our aim was to determine, whether HTT results predict the risk of repeated episodes of exertional heat illness (EHI). DesignRetrospective cohort. MethodsOne-hundred-forty-five subjects (110 HT, 35 HI) who were diagnosed with an EHI event by a physician and underwent HTT during 2008–2015 were contacted and asked about recurrence of EHI. Incidence of recurrent events was reported as number of cases per 1000 person-years. Ratio of events among HI and HT individuals was presented as rate ratio (RR) and its 95% confidence interval. ResultsOf the 145 patients, six (4.1%) had experienced recurrent EHI events (10.63 per 1000PY): four HI subjects (11.4%, 26.6 per 1000PY) and two HT (1.8%, 4.8 per 1000PY) (RR=5.504, CI 95%=1.01–30, p=0.027). Only one of the six recurrent events was a heat stroke (HT individual), other five were heat exhaustions. Sensitivity, specificity and diagnostic accuracy of HTT were 66.7%, 77.7% and 77.2%, respectively. ConclusionsThe risk of EHI recurrence is measurable and can be discussed with patients before they return to sports. A referral to HTT can be considered, as negative HTT result is associated with substantial and significant EHI risk reduction.

Heat Acclimatization and Exertional Heat Illness Prevention in Youth Football Programs

ABSTRACT ATHLETES ARE AT AN INCREASED RISK OF EXPERIENCING AN EXERTIONAL HEAT ILLNESS (EHI) DUE TO THE PHYSICAL EXERTION REQUIRED BY FOOTBALL, PARTICULARLY WHEN PERFORMED IN HOT AND HUMID CONDITIONS. VARIOUS MODIFICATIONS TOGETHER WITH EDUCATION AND PREPARATION BY THOSE WORKING WITH YOUTH FOOTBALL ATHLETES CAN HELP MITIGATE THE RISKS OF EXERCISING IN THE HEAT. THE OVERALL EHI RISK FOR YOUTH ATHLETES IS NOT WELL KNOWN. THE PURPOSE OF THIS ARTICLE IS TO REVIEW THE EXISTING LITERATURE REGARDING THERMOREGULATION OF YOUNGER ATHLETES AND TO PROVIDE GUIDELINES FOR COACHES AND CLINICIANS ON HOW TO PREVENT EHI FOR SAFER PARTICIPATION IN YOUTH FOOTBALL.

大学新入生の熱中症発生頻度：体育系学部新入生と一般学部新入生の比較

Purpose: Guidelines for prevention of exertional heat illness issued by academic societies and the Japan Sports Association have been well structured. Although these guidelines have been widely disseminated, the numbers of adolescents suffering heat illness during sports activities is still a concern. Many freshman enrolled in Sports Science-related Departments (SSD) are presumably high-level athletes who engage in high-intensity and/or long-duration exercise during daily practice, and could thus be categorized as a group at high risk of exertional heat illness (EHI). Conversely, the majority of freshman enrolled in non-Sports Science-related Departments (non-SSD) are presumably low-level athletes who might be engaged in comparatively less high-intensity and/or short-duration exercise during daily practice, and could thus be categorized as a group at low risk of EHI. Although sports activities are known to increase the risk of EHI, no evidence is available to suggest whether high-level sports activities increase the risk of EHI. The purpose of the present study was to clarify the prevalence of EHI in SSD and non-SSD freshman. Methods: Four hundred eighty students from SSD and 447 students from non-SSD participated in a self-assessed survey designed to clarify the prevalence of EHI experienced by individuals during the period from elementary school to high school age. Chi-squared and post-hoc residual analysis, and odds ratio (OR), were used to compare differences between the groups. Results: Completed survey questionnaires were received from 480 SSD students and 447 non-SSD students. The prevalence of heat illness was 31.9% in the SSD group and 16.8% in the non-SSD group [adjusted OR 2.342, 95% confidence interval (CI) 1.712, 3.204]. The number of times individuals had experienced heat illness in the past differed between the SSD and non-SSD groups, but the response ratio was similar. More than 85% of students in both groups who had suffered heat illness in the past had done so during club activities at junior high school and high school. The ratio of students who reported ever suffering from heat illness during sports club activities at junior high school and/or high school (n=860) was 25.6%, whereas 13.4% of students reported that they had never participated in junior high school and/or high school sports club activities during the same period (n=67). Conclusion: The present study revealed that high-level athletes (SSD freshman) had experienced EHI twice as often as non-SSD students. In addition, students who had participated in sports club activities at junior high school and/or high school had suffered EHI twice as often as students who had not participated in sports club activities. Coaches and athletes should take more care to prevent EHI during sports and/or physical activities, and when it occurs, steps should be taken to prevent progression to exertional heat stroke.

Implementing Exertional Heat Illness Prevention Strategies in US High School Football

Approximately 6500 high school football athletes are treated annually for exertional heat illness (EHI). In 2009, the National Athletic Trainers Association (NATA)-led Inter-Association Task Force (NATA-IATF) released preseason heat acclimatization guidelines to help athletes become accustomed to environmental factors contributing to EHI. This study examines compliance with NATA-IATF guidelines and related EHI prevention strategies. The study used a cross-sectional survey completed by 1142 certified athletic trainers (AT), which captured compliance with 17 NATA-IATF guidelines and EHI prevention strategies in high school football during the 2011 preseason. On average, AT reported football programs complying with 10.4 NATA-IATF guidelines (SD = 3.2); 29 AT (2.5%) reported compliance with all 17. Guidelines with the lowest compliance were as follows: "Single-practice days consisted of practice no more than three hours in length" (39.7%); and "During days 3-5 of acclimatization, only helmets and shoulder pads should be worn" (39.0%). An average of 7.6 EHI prevention strategies (SD = 2.5) were used. Common EHI prevention strategies were as follows: having ice bags/cooler available (98.5%) and having a policy with written instructions for initiating emergency medical service response (87.8%). Programs in states with mandated guidelines had higher levels of compliance with guidelines and greater prevalence of EHI prevention strategies. A low proportion of surveyed high school football programs fully complied with all 17 NATA-IATF guidelines. However, many EHI prevention strategies were voluntarily implemented. State-level mandated EHI prevention guidelines may increase compliance with recognized best practices recommendations. Ongoing longitudinal monitoring of compliance is also recommended.

Death by Water Intoxication

With recent emphasis on increased water intake during exercise for the prevention of dehydration and exertional heat illness, there has been an increase in cases of hyponatremia related to excessive water intake. This article reviews several recent military cases and three deaths that have occurred as a result of overhydration, with resultant hyponatremia and cerebral edema. All of these cases are associated with more than 5 L (usually 10-20 L) of water intake during a period of a few hours. The importance of maintaining adequate hydration in exertional heat illness prevention cannot be overemphasized, but excessive fluid intake may lead to life-threatening hyponatremia. Current guidelines provide safety by limiting fluid intake during times of heavy sweating to 1 to 1.5 L per hour.

Reducing Exercise-related Sudden Cardiac Death Rates Among Recruits by Prevention of Exertional Heat Illness

Reducing Exercise-related Sudden Cardiac Death Rates Among Recruits by Prevention of Exertional Heat Illness

Reducing exercise-related sudden cardiac death rates among recruits by prevention of exertional heat illness

Reducing exercise-related sudden cardiac death rates among recruits by prevention of exertional heat illness