During the past decade, a number of advances have been made in understanding the adverse effects of environmental heat. Among these have been important, even spectacular observations on certain chemical, biophysical, and physiological events that take place during performance of hard work in hot environments. In turn, these observations have permitted formulation of new concepts concerning the pathogenesis of the form of heat stroke that generally occurs in otherwise healthy young men during intensive physical conditioning programs. This type of heat stroke, in contrast to the classical form that characteristically affects the ill or the aged, often carries a high mortality, in those who survive its initial hours, there commonly appear widespread, often catastrophic complications.
The purpose of this review is threefold: first, to summarize important elements from an extensive literature concerning physiologic events that occur as an individual becomes acclimatized to work in the heat; second, to relate these