218 THE HEAT OF THE BODY 



mechanism. More heat than usual is generated in the 

 body because of the poisonous substances developed by 

 the microbes which are responsible for the fever. Be- 

 cause of the derangement of the heat-controlling mech- 

 anism, the secretion of perspiration fails and the blood 

 cannot therefore be cooled by its evaporation. There is 

 therefore an excess of heat to be removed and a de- 

 fective mechanism to accomplish its removal. As a result, 

 much of the heat remains in the body and raises its 

 temperature. 



Since fever has a most harmful effect upon the body, 

 especially upon the nerves and brain, it is important 

 that the body temperature should be kept down as much 

 as possible. To accomplish this, it is customary to give 

 a person with pronounced fever, cooling drinks, appli- 

 cations of ice, and cold baths, in order to aid in removing 

 the excess heat from the body. 



EXPERIMENTS AND DEMONSTRATIONS 



Materials: Clinical thermometer; dairy thermometer; pieces 

 of wool, linen, cotton and silk ; ice ; microscope. 



1) Skin temperature: Place bulb of dairy thermometer on 

 back of hand and cover with piece of dry woolen cloth. Watch 

 mercury column and when it no longer rises (5 or 10 min.) 

 record temperature. 



2) Internal temperature: a) Having carefully shaken mer- 

 cury column of clinical thermometer below 98 F., place bulb 

 under tongue and close lips. Read temperature at end of 5 min. 



b) Hold piece of ice in mouth for a few minutes. Having 

 shaken mercury column down to 90 F., take temperature of 

 mouth. 



3) Examine under microscope fibres of pure linen, silk, cot- 

 ton and wool. Observe and sketch characteristic appearances. 



