Abstract des Autors

The authors have determined the coefficient of evaporative heat loss of the human body (he) by means of humidity steps in low air movement (Va<0,2 m/s). Such a determination requires a fully wetted skin and this implies therefore some loss of dripping sweat. The collection of this dripping sweat allows the determination of the total evaporation; this evaporation exists on the skin surface and around the drops during their fall from the skin to the oil pan where dripping sweat is collected. An estimation of this dripping sweat evaporation allows to assess the skin evaporation and,consequently, the evaporative coefficient he. In these experimental conditions: E = S - SNE - 0.005 SNE (PsH20-PaH20) where E is the skin evaporative rate (g/h); S = total sweat rate (g/h); SNE = the nonevaporative sweat rate (g/h); PSH20 = the partial pressure of satured water (at Ts) on skin (mb) and PaH20 the partial pressure of water vapor in ambient air (mb). The coefficient of evaporative heat loss in low air movement thus found, is 5.18 +/- 0.22 W/m2 x mb.