Acclimation to humid heat lowers resting core temperature

Departments of Biology and Exercise and Nutritional Sciences, San Diego State University, San Diego 92182; and Naval Health Research Center, Applied Physiology Division, San Diego, California 92186 The purpose of this study was to test the hypothesis that a reduction in resting rectal temperature (T re ) is partially responsible for the attenuation in the rise of core temperature during heat exposure following acclimation to humid heat. Nine male volunteers completed 7 days of acclimation, performing 2 h of exercise per day in a hot, humid environment (35°C, 75% relative humidity). Mean (±SD) ending T re significantly ( P