378 STUDIES IX ADVAXCKD PHYSIOLOGY. 



lowest temperature is in the most exposed portions of the 

 skin, such as the ear flaps, where on account of the ex- 

 cessive radiation of heat it may sink materially. 



So far the variations in temperature have been normal 

 variations. In addition, however, to these there occur the 

 variations caused by external agents, either by the immedi- 

 ate surroundings or by pathological conditions within the 

 system. The limits of temperature which may be so pro- 

 duced are considerable. One of the lowest temperatures 

 recorded is 24 6 /ioC., the temperature of a drunken man. 

 The upper limits have been reached in fevers, when the 

 temperature may rise from 37 5 /io to 41 5 /io C. Expressed 

 in Fahrenheit degrees, the variations in temperature are 

 from 76, in the case of the drunkard, to 106, in the case 

 of fevers. Sometimes just before death temperatures from 

 110 to 113 have been recorded. 



CONDITIONS AFFECTING THE TEMPERATURE. 



The temperature is affected in a number of ways. The 

 first and most apparent agency is, of course, the external 

 environment. The temperature is higher on an average in 

 summer than in winter. It is increased by taking hot 

 things into the stomach, or by subjecting the whole body 

 to a hot bath. 



Secondly, the most usual agency affecting the tempera- 

 ture is the oxidation in the body. When this oxidation in- 

 creases, as in the case of muscular work or exertions of any 

 kind, the temperature increases along with it. It is the 

 commonest experience of course that hard work makes one 

 warm . 



A third agency affecting the temperature is the blood- 

 flow, especially through the skin. When the blood-vessels 

 in the skin are dilated and much blood traverses it, it is 

 there exposed to the radiating influences and is materially 

 cooled. On the other hand, when the blood-vessels of the 

 skin are contracted and little blood passes through there, 

 much less opportunity is given for the heat to radiate from 



