ABSTRACT
Heat strain includes changes in body temperature, heart rate, and sweating. During exposures to heat stress, the temperature of most body compartments increases, and these changes facilitate the removal of heat from the body. Core temperature is an important measure of heat strain. Blood ¢ow moves heat from the deep body tissues, including working muscles where it is generated, to the skin, where it is dissipated. Heart rate re¢ects the cardiovascular response to blood ¢ow requirements and is a sensitive indicator of physiological strain due to both work demands and heat stress. Finally, sweating ensues to provide for evaporative cooling of the body.
