Evidence-based Medicine (CEBM) 1 level-2 evidence or higher, with PEDro scores ≥5 Exclusion • Studies that used passive heating techniques rather than exercise to induce hyperthermia • Studies that cooled subjects during exercise (ie, percooling) • Studies that cooled subjects between exercise bouts
Timothy M. Wohlfert and Kevin C. Miller
Kailin C. Parker, Rachel R. Shelton, and Rebecca M. Lopez
Question Do alternative cooling methods have effective core body temperature cooling rates for hyperthermia compared with previously established CWI cooling rates? Summary of Key Findings We searched for randomized clinical trials that used alternative methods of cooling that were applied on exercising
Kayla E. Boehm and Kevin C. Miller
recommendations for exertional heat stroke (EHS) victims (ie, 0.15°C/min). 5 Table 1 Characteristics of Included Studies Authors Armstrong et al 3 DeMartini et al 4 Lemire et al 2 Patients, n 8000 athletes. 21 (35  y) were diagnosed with extreme hyperthermia and either heat exhaustion or EHS. 17 males (age
Robert Carter III, Samuel N. Cheuvront, and Michael N. Sawka
We report our observations on one soldier with abnormal hyperthermia during exercise in the heat compared with prior exercise and following acute local (non-febrile) infection. Also, we report on 994 heat stroke hospitalizations in the U.S. Army. It is known that prior infection is a risk factor for heat illness and some of the 37 heat stroke deaths cited infections (eg, pneumonia, influenza) in the medical records.
This case report illustrates complete recovery from abnormal hyperthermia, which occurred in a laboratory setting during mild, low intensity exercise. In a field setting, this case may have resulted in serious heat illness. As with most of the heat stroke cases, rapid medical attention (ie, cooling and rehydration) and the age group (19 to 26) that represents majority of the heatstroke cases in U.S. Army are likely factors that contribute successful treatment of heatstroke in the field environment.
We conclude that acute inflammatory response can augment the hyperthermia of exercise and possibly increase heat illness susceptibility. Furthermore, it is important for health care providers of soldiers and athletes to monitor acute local infections due to the potential thermoregulatory consequences during exercise in the heat.
Tal Marom, David Itskoviz, Haim Lavon, and Ishay Ostfeld
Exertional heat stroke (EHS) is a major concern in military trainees performing intense physical exercise, with substantial morbidity rates. Prehospital diagnosis of EHS is essentially clinical. Thus, soldiers, command personnel, and medical staff are taught to recognize this injury and immediately begin aggressive treatment to prevent further deterioration.
Patients and Methods:
During 2007, 5 otherwise healthy Israeli Defense Forces (IDF) soldiers were diagnosed with EHS while performing strenuous exercise. They were treated vigorously according to the IDF EHS-treatment protocol and were referred to the emergency department.
On arrival at the emergency department, physical examination including rectal temperature was unremarkable in all soldiers. Blood and urine workup showed near-normal values. No other medical conditions that could have explained the clinical presentation were found. All soldiers were discharged shortly afterward, with no further consequences. A heat-tolerance test was performed several weeks after the event and was interpreted as normal. All soldiers returned to active service.
Because the initial clinical findings were very suggestive of EHS and because no other condition could have explained the prehospital transient hyperthermia, we suggest that these soldiers were correctly diagnosed with EHS, and we propose that rapid vigorous cooling prevented further deterioration and complications. We suggest calling this condition aborted heat stroke.
Tyler T. Truxton and Kevin C. Miller
Exertional heat stroke (EHS) is a medical emergency which, if left untreated, can result in death. The standard of care for EHS patients includes confirmation of hyperthermia via rectal temperature (Trec) and then immediate cold-water immersion (CWI). While CWI is the fastest way to reduce Trec, it may be difficult to lower and maintain water bath temperature in the recommended ranges (1.7°C–15°C [35°F–59°F]) because of limited access to ice and/or the bath being exposed to high ambient temperatures for long periods of time. Determining if Trec cooling rates are acceptable (ie, >0.08°C/min) when significantly hyperthermic humans are immersed in temperate water (ie, ≥20°C [68°F]) has applications for how EHS patients are treated in the field.
Are Trec cooling rates acceptable (≥0.08°C/min) when significantly hyperthermic humans are immersed in temperate water?
Summary of Findings:
Trec cooling rates of hyperthermic humans immersed in temperate water (≥20°C [68°F]) ranged from 0.06°C/min to 0.19°C/min. The average Trec cooling rate for all examined studies was 0.11±0.06°C/min.
Clinical Bottom Line:
Temperature water immersion (TWI) provides acceptable (ie, >0.08°C/min) Trec cooling rates for hyperthermic humans post-exercise. However, CWI cooling rates are higher and should be used if feasible (eg, access to ice, shaded treatment areas).
Strength of Recommendation:
The majority of evidence (eg, Level 2 studies with PEDro scores ≥5) suggests TWI provides acceptable, though not ideal, Trec cooling. If possible, CWI should be used instead of TWI in EHS scenarios.
Grace Katt and Kevin C. Miller
.g., sauna) instead of exercise to develop hyperthermia. • Studies where any type of cooling was performed before (i.e., precooling) or during (i.e., percooling) testing. Evidence Quality Assessment Each study was scored independently by the two authors using the 2011 Oxford Center for Evidence-Based Medicine
Mitchell J. Henderson, Bryna C.R. Chrismas, Christopher J. Stevens, Aaron J. Coutts, and Lee Taylor
) recovery tool for rugby sevens athletes, proposed to control hyperthermia, reduce muscle inflammation and damage, and decrease muscle soreness. 9 However, the efficacy of rugby sevens specific CWI protocols, 10 within a real-world elite tournament scenario, is not available (eg, total heat storage as a
Mitchell J. Henderson, Bryna C.R. Chrismas, Christopher J. Stevens, Andrew Novak, Job Fransen, Aaron J. Coutts, and Lee Taylor
performance and protect athlete health (particularly in female athletes who may be more susceptible to hyperthermia 4 ). This is the first study to directly compare player Tc recorded in training to the only available match-play Tc data in women’s rugby sevens. The findings support that training in hot