HEAT: MAN'S EXCHANGES AND PHYSIOLOGICAL RESPONSES

Abstract

The purpose of this paper is to summarize the applications of physical laws of heat transfer to the analysis of thermal re lations between man and his environment; to review briefly the important recent work on the physiological responses of man to heat, and to emphasize some of the studies carried out during the war years which have advanced knowledge in this field. The authors consider briefly certain algebraic relationships, including the heat balance equation, coefficients of heat exchange by radiation, convection, and evaporation, the equilibrium state, equivalent environments, and physical methods for measuring equivalence. The physiologic considerations include body temperature and gradients, peripheral blood flow, circulation, sweating, salt depletion, metabolism (caloric requirements, specific dynamic action of proteins, vitamin requirements), disturbances of the gastro-enteric tract, thermal regulation, acclimatization, work in hot environments, upper limits of tolerance, and heat disease.