HEAT PRODUCTION OF THE HUMAN BODY 



The experienced engineer on examining 

 the gradients of Table V will see immedi- 

 ately that there are two classes of effects 



at 37°C to the skin, why does the thermal 

 head vary from 8° at a temperature of 25°C 

 to 2° at 35°C? This mechanism for altering 



Fig. 1. Electrically heated copper mannikin d! 1 s in.-' Innly ;m'a whose heat production may be regu- 

 lated to correspond to either resting or exercising heat production. Devices of this type are frequently 

 used to estimate the protective value of various clothing assemblages. Temperatures shown in °C 

 are skin, clothing, and environmental temperatures, as observed in seated subjects normally clothed and 

 comfortable. Conditions in °F, Air and Wall 72°, Th (head) 92.1°, Tt (trunk 94.1 °, Tr ) upper e.xtremi- 

 ties) 91.0°, Tl (lower extremities) 88.9°, Average Skin 91.0°, Average Clothing 87°, Air Velocity 15-25 

 feet per minute. 



operating to keep the deep body temperature 

 constant. He will ask: Since a constant 

 quantity of heat is passing from the region 



the internal gradient must be an important 

 part of human heat regulation. 



This supposition is correct and the 



