

CONTROL OF BODY TEMPERATURE AND FEVER 753 



The Heat-regulating Center 



In all discussions on the regulation of body temperature and the 

 causes of fever, it is assumed that a heat-regulating or thermogenic 

 center exists somewhere in the brain. It is believed to be located 

 about the optic thalami or corpora striata, for it has been found in 

 rabbits that destruction of the brain anterior to this region does not 

 cause any change in body temperature, whereas destruction behind it 

 is followed by an entire upset in the heat-regulating mechanism. Fur- 

 thermore, artificial puncture of this part of the brain causes marked 

 elevation in body temperature in rabbits (heat puncture). Most in- 

 teresting experiments have been recorded by Barbour, 56 who succeeded 

 in applying heat or cold locally in the region of the centers. By the 

 application of cold, increased muscular metabolism, on the one hand, 

 and diminished heat loss, on the other, were excited; and conversely, 

 when warmth was applied, an increased heat loss and a diminished heat 

 production were observed. Irritation of this region of the brain in man, 

 as after cerebral hemorrhage, is also accompanied by remarkable dis- 

 turbances in heat regulation. It is believed by many that the essential 

 cause of fever in infective conditions, is an action on these centers by toxic 

 substances which develop in the blood. 



Significance of Fever to the Organism 



It is impossible at present to state definitely whether fever is a re- 

 action of the organism against some infection and therefore of benefit 

 in assisting the organism to combat it, or whether it is in itself an un- 

 favorable condition. The question can certainly not be answered by 

 observing the behavior of bacteria growing at different temperatures 

 in various media outside the body. That certain bacteria should be 

 found not to thrive at incubator temperatures equal to those found in 

 the body during fever, does not at all prove that this fever is of sig- 

 nificance as a means of combating the growth of the bacteria in the 

 body. It is undoubted that, where the body temperature becomes ex- 

 cessively high, the correct treatment is to keep it down as much as 

 possible. On the other hand, the reduced mortality that has followed 

 the introduction of the cold-bath treatment in typhoid fever may not 

 be due so much to the reduction in body temperature itself as to 

 the favorable effect produced on the nervous system and circulation. 

 We certainly know that in normal animals moderate degrees of hyper- 

 pyrexia brought about by exposure to moist heat are well borne for consider- 

 able periods of time, thus indicating that it is the infection and not the 

 hyperthermia that causes the serious damage to the body in infectious 

 fevers. 



