Human surface to mass ratio and core temperature in exercise heat stress - a concept revisited

The effects of morphological factors (body surface area (A(D)), body mass and surface to mass ratio (A(D)/M)) on exercise heat stress responses in a hot wet (HW) (35 degreesC 80% rh) and hot dry (HD) climate (45 degreesC, 20% rh) of equal WBGT (similar or equal to 31.6 degreesC) were studied in 30 and 25 subjects respectively. In both climates there were positive correlations of T-rc with A(D)/M, negative with A(D) and mass, giving the bigger subjects an "advantage" that remained (A(D)/M) when data were corrected for differences in V over dot (O2max), which accounted for a substantial part of the variance in T-re. The observed A(D)/M effect contradicts earlier studies but is consistent with model calculations. (C) 2001 Elsevier Science Ltd. All rights reserved.