ADAPTATIONS OF HUMAN BODY TO VARYING THERMAL CONDITIONS 



293 



American Society of Heating and Ventilating 

 Engineers (2) compares the two sets of data 

 in a graph which shows general concordance. 



Comparison of Nude and Clothed Subjects 



With Respect to the Temperature Ranges 



of the Zones of Heat Regulation 



The relative reaction of nude and clothed 

 subjects in terms of skin temperature and the 



the nude subjects is given in Fig. 6 as 29°- 

 31°C, which is narrower than that of 28°- 

 33 °C quoted in a preceding paragraph. This 

 is not an experimental difference, but reflects 

 the present belief of the authors that the 

 essential characteristic of the middle zone is 

 unstressed thermal equilibrium rather than 

 strict vasomotor control with minimal 

 evaporation. 



2 ^0 



22 



40 

 35 

 30 



^ 20 



O »"0H NUPE SUBJECTS 



iaP€«**1VE TEMPtWATUPE IN "C 



Fig. 6. Comparison of mean skin temperature and conductance (internal regions to skin surface) 

 of resting clothed and nude subjects with respect to the environmental temperatures associated 

 with the three zones of heat regulation. 



different phases of regulation for different 

 operative temperatures may be compared in 

 Fig. 6, which is based on data reported by 

 Gagge, Winslow, and Herrington (17). The 

 range of the zone of vasomotor regulation for 



In general the effect of clothing is to 

 broaden the central zone of vasomotor con- 

 trol and moderate sweat secretion, and to 

 reduce the cooling effect below this zone and 

 exaggerate the heating effect in the region 



