Body Cooling in Hyperthermic Males and Females

Exertional heat stroke (EHS) is an emergency medical condition that is prevalent in military soldiers, athletes, and laborers. It is diagnosed when the rectal temperature is above 40°C with the presence of central nervous dysfunction (altered mental status). The gold standard method of care for EHS is immediate onsite whole body cooling using cold-water immersion (cooling rates \>0.15°C•min-1), which is reported to have the highest cooling rate. In the treatment of EHS, selecting a cooling modality with a high cooling rate becomes crucial to minimize the time above the critical threshold of body temperature at 40°C to less than 30 minutes for the best chance of survival and to minimize the severity of prognosis. However, in situations where cold water immersion is not feasible (in certain military, firefighter, or other remote settings), other cooling modalities must be available that have a cooling capacity similar to that of cold-water immersion. In this proposed study, we aim to compare the cooling rates of the Polar Breeze® (developed by Polar Breeze ®, Clearwater, FL), cold-water immersion (the current gold standard for EHS treatment), and passive cooling in individuals with exercise-induced hyperthermia