Proceedings of The Fiph Int. Con $ on Environmml Ergonomics INDIVIDUAL CHARACTERISTICS AND RESPONSE TO HEAT STRESS

The purpose of this paper is to provide an overview of those individual characteristics which have the ability to, or have been purported to, influence physiological responses to heat stress. This overview is based on studies which are, for the most part, cross-sectional in design and singular in focus. As used here, "individual characteristics " refer to physical or physiological traits which are not readily modifiable within a relatively short time h e. Therefore, such factors as heat acclimation and hydration state are not included. Those individual characteristics covered are gender, age (including menopausal status), race, body size and composition, and VoZmaX. Furthermore, there is a propensity to use the general (but typically illdefined) term "heat tolerance " in the vast body of literature which relates to individual charactmistics and heat stress. In the interest of clarifying the often contradictory findings in this area, the present paper divides the vague notion of "heat tolerance " into 2 distinct levels of response Variables- body core temperature responses and heat loss effector responses (sweating, skin vasodilatation, etc.). It is important to note that these 2 related response outcomes are often not directly linked, e.g. a lower sweating rate does not necessarily result in a higher body core temperature