CHAPTEK II 

 THE APPLIED PHYSIOLOGY OF BODY HEAT 



HEAT is to be regarded as a by-product of the metabolic 

 processes described in the last chapter. It is not a thing 

 which the living body manufactures, as it does a secre- 

 tion, for its own sake ; on the contrary, life and heat 

 are inseparable, and so long as life exists in the body, so 

 long will heat continue to be produced. It is important 

 to make this clear, for there is still a tendency to regard 

 heat as something which is produced, as it were, by an 

 effort, simply in order to keep the body warm. So far 

 from this being the case, the ordinary processes of 

 metabolism result in normal conditions in the production 

 of considerably more heat than is really required to 

 maintain the body temperature at its usual level. It 

 has been calculated, indeed, that were it not for the fact 

 that heat is constantly being lost from the body, a man 

 of 10 stones in weight, with the usual metabolic turn- 

 over of 3,000 Calories, would reach boiling-point in 

 thirty-five hours ! The greater the degree of ' vitality,' 

 the larger, naturally, is the amount of heat produced. 

 Hence, any agent which tends to paralyze the proto- 

 plasm of the body cells brings about a diminished pro- 

 duction of heat. Alcohol and anaesthetics are amongst 

 such agents, and it is a well-known fact that cold is 



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