ANIMAL HEAT 183 



to prevent the body temperature from rising or falling. 

 Very strong cooling also disturbs the regulation of tempera- 

 ture by paralyzing the muscles of the blood vessels so that 

 the cutaneous vessels become dilated to an abnormal extent. 

 When the temperature regulation fails, the body temperature 

 speedily sinks below 19 or rises about 42 and death results. 

 In fever, the regulation of temperature is disturbed ; the 

 production of heat is increased, hence the body temperature 

 is abnormally high. 



Within certain limits, the heat production in cold-blooded 

 animals is the larger, the higher the temperature of the external 

 medium, for, in these animals, the intensity of the combustion 

 taking place in the body increases with the raising of the external 

 temperature. 



