HEAT-FLUX AND STORAGE IN HOT ENVIRONMENTS

When humans are exposed to extreme ambient temperatures, or generate i nternal heat by exercise, the body strives to maintain internal body t emperature. The core and skin temperatures attained, as well as the ph ysiological adjustments necesssary to minimize temperature excursions, are governed by (i) heat generated by working muscle, (ii) external w ork performed, and (iii) biophysical heat exchange with the thermal en vironment. This paper provides an overview of these avenues of heat pr oduction and exchange, the aspects of the thermal environment which di ctate the direction and magnitude of that exchange, and the mean body temperature response from a simplified biophysical perspective.