CHAPTER XVII 



SOME SPECIAL REGULATIVE PROCESSES 



REGULATION OF TEMPERATURE 



579. Necessity for Regulation. Man lives in the torrid 

 zone and in the frigid zone, yet his temperature remains 

 the same as he goes from one zone to another, and as 

 summer changes to winter. The temperature of the 

 healthy body is about 98.6 F. This is unmistakable 

 evidence that some means of maintaining a uniform 

 temperature exists in his body. The wonderful ease 

 with which the human body maintains a normal tempera- 

 ture when exposed to extremes of heat and cold is a fasci- 

 nating and instructive subject for study; but it remains 

 partly a mystery, and the mechanism by which this end is 

 attained has never been fully explained. 



580. The Highest Temperature which living tissue may 

 reach without destroying life is 113 F., but it could remain 

 at such a temperature only a short time. 1 "A man can 

 for a short time remain in an oven heated to the boil- 

 ing point of water (212 F.), provided the air is dry. With 

 felt slippers on his feet he could stand there while his dinner 

 cooked beside him. He is able to do this owing to the pro- 

 fuse perspiration which pours from his skin and cools his 

 body by evaporation. If the oven were full of steam, the 



1 Once a man took the pulse of his daughter who was ill, and found it to be 

 1 20. He was greatly alarmed, and summoned several physicians. He had 

 confused the pulse with the temperature. The pulse rate during vigorous 

 exercise sometimes reaches 160 per minute. 



320 



