CHAPTER XX 



THE HEAT OF THE BODY 



390. Inanimate bodies tend constantly to assume the 

 temperature of the air, water, or other objects near them. 

 An object which has been heated gives out heat to sur- 

 rounding objects until all are of the same temperature. 

 There is, as we say, a tendency to equilibrium in respect 

 to temperature. 



391. Animal Heat. Warm-blooded animals (birds and 

 mammals) maintain within their bodies, summer and win- 

 ter and indoors and out, with slight variations, the same 

 degree of heat, and are independent of their surroundings 

 in that respect. 



392. Temperature of the Body. In order that the vital 

 processes necessary to human health and comfort may go 

 on under the most favorable circumstances, it is necessary 

 that the body should maintain a temperature of from 98 

 to 99 F. (from 36.6 to 37.2 C.). If it rises much above 

 or sinks much below this, it is an important indication of 

 abnormal condition in some part of the system. We may 

 be exposed to extreme heat and to severe cold without any 

 marked change in the bodily heat. The skin, it is true, 

 being in contact with external" objects, is usually cooler 

 than other parts. Some of the internal organs have in 

 health a temperature several degrees higher than the gen- 

 eral average, and any special activity of an organ develops 



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