THE TEMPERATURE OF THE BODY 



493 



The rectal temperature is normally about 99-6 F., the " urine " tem- 

 perature about 99 F. 



Owing to the loss of heat from the surface, the temperature of the 

 skin is not so constant as the internal temperature of the body; in 

 fact, it shows considerable variation according to the surrounding 

 conditions. For example: 



Chest 



Cheek 



Neck 



Back of hand 



Arm . . 



Abdomen 



Leg .. 



Indoors. 



30 C. 

 32i C. 

 33 s C. 

 31 C. 

 31C. 

 33 C. 

 32 C. 



Ten Minutes after 

 a Swim in Sea. 



24 C. 



25 C. 



31 s C. 



24 C. 



29 C. 



26 C. 



30 C. 



In a cold wind the cheek temperature may be as low as 15 C. In 

 hot, moist atmospheres the skin temperature rises up to the internal 

 temperature of the body. Too much uniformity of skin temperature 

 is undesirable. > 



p.m. 



F. 



789 10 11 12 12 3456 789 10 11 12 12 34-5 



C. 



FIG. 234. DAILY VARIATION OF TEMPERATURE OF MAN. (M. S. Pembrey.) 



While the rectal temperature represents the body temperature, 

 that of the mouth rises and falls with the cooling power of the atmo- 

 sphere. It is therefore illusory to fix the mouth temperature at any 

 given figure. In the Arctic region, when the outside temperature 

 ranged from 12 to 30 C. beloAv zero, and that of the engine-room of 

 the ship was 37 C., the mouth temperature varied from 34-58 C. to 

 37-45 C. i.e., 5-17 F. The mouth is cooled through the floor of 

 the mouth rather than through the inspired air. After drinking hot 

 fluid, the mouth will give too high a reading. 



The temperature of man shows a daily variation dependent for 

 the most part upon muscular activity. It rises during the day to 

 a maximum about 6 p.m., and falls during the night to a minimum 

 about 2.30 to 3 a.m. Night work, depending largely upon its severity, 



