HEAT 



309 



acclimatized or merely in another atmosphere, the mode of recov- 

 ery might be quite different. That the production of heat may 

 augment in such heat deficits may be computed from earlier data 

 collected by Yagloglou ( '24). The loads coincident with each rate 

 of heat gain there reported may be estimated from (l) the fact 

 that rectal temperature did not change more than 0.3° C, (2) the 

 correlation between effective temperature and skin temperature, 

 and (3) the computation of mean body temperature according to 

 Burton's ('35) method. 



Whereas in heat deficits the heat loss is ascertained from heat 

 production minus net gain of heat content, in heat excesses the heat 

 loss happens itself to be measured (fig. 146) and heat production 

 is found by subtraction. 



+2 +4 



Heat Load — Caljkq. 

 Fig. 146. Eate of heat exchange in relation to heat load. Total heat equilibration 

 diagram. In the range of + AH, a single experiment is represented, on a man after 

 heat accumulated from indoor exercise. Loads or heat storages were estimated from 

 rectal temperatures alone. Heat output was the sum of vaporization (from weight loss), 

 radiation (from radiometric sampling), and convection (estimated) during periods of 

 0.32 hour; heat production was estimated from output plus storage; all by Hardy et al. 

 ( '38, p. 489) whose data are plotted. In the range of -AH, the data are new ones of 

 Pinson and Adolph and represent recoveries after drinking ice water. An extreme 

 limit of -AH is designated for heat production from data of Winslow et al. ( '37, p. 8). 



The properties of the equilibration diagram for heat (fig. 146) 

 are similar to those of the diagram for water. Total gain exceeds 

 total loss in deficits, and is less than total loss in excesses. Only 

 at one point (zero load) are gains and losses equal. In the dia- 

 gram, the net losses in excesses are much faster than the net gains 

 in equal deficits. 



Often the measurement of heat production (gain) is termed in- 

 direct calorimetry, of heat loss direct calorimetry. The word 



