“…Indeed, DH b is employed extensively as both a physiological criterion for maximal heat exposure (Blockley et al, 1954;Henane and Bittel, 1975;Holmer, 1989;Iampietro and Goldman, 1965;Kaufman, 1963), and as an analytical tool for assessing the thermal status of an individual for a wide range of subpopulations (Arngrimsson et al, 2004;Boot et al, 2006;Saunders et al, 2005;Webborn et al, 2005). In theory, the measurement of body heat exchange using simultaneous measures of total heat production and loss is the only method whereby DH b can be directly determined.…”