326 



VARIATIONS OF TEMPERATURE. 



denied. The difference is comparatively trivial, when we remember that a man is 

 subjected to a variation of over 40 C. in passing from the equator to the poles. 

 Observations on more than 4000 persons show that when a person goes from a 

 warm to* a cold climate, his temperature is but slightly diminished, but when he 

 goes from a cold to a warm climate his temperature rises relatively considerably 

 more. In the temjterate zone, the temperature of the body during a cold winter is 

 usuallv 0T to 03 C. lower than it is on a warm summer day. The elevation of 

 a place above sea-level has no obvious effect on the temperature of the body. 

 There seems to be no difference in different races, nor in the sexes, other conditions 

 being the same. Persons of powerful physique and constitution are said to have 

 generally a slightly higher temperature than feeble, weak, anaemic persons. 



(2) Influence of the General Metabolism. As the formation of heat depends 

 upon the transformation of chemical compounds, whose chief final products, in 

 addition to H 2 0, are C0. 2 and urea, the amount of heat formed must go pari }>assu 

 with the amount of these" excreta. The more rapid metabolism which sets in after 

 a full meal causes a rise of temperature to several tenths of a degree (" Digestion- 

 fever "). As the metabolism is much diminished during hunger, this explains why 

 the mean temperature in a fasting man is 36 '6, while it is 37*17 on ordinary days 

 d 237). 



Jiirgensen also found that the temperature fell on the first day of inanition (although there 

 was a temporary rise on the second day). In experiments made upon starving animals, the 

 temperature at first fell rapidly, then remained constant for a considerable time, while during 

 the last davs it fell considerably. Schmidt starved a cat on the 15th day the temperature was 

 33'6; on the 16th, 38-3; 17th, 37*64; 18th, 35*8; 19th (death) = 33*0. Chossat found that 

 starving mammals and birds had a temperature 16 C. below normal on the day of their death. 



(3) Age has a decided effect upon the temperature of the body. The extent of 

 the general metabolism is in part an index of the heat of the body at different ages, 

 but it is possible that other, as yet unknown, influences are also active. 



Newly-born animals exhibit peculiarities owing to the sudden change in their 

 conditions of existence. Immediately after birth, the infant is 0*3 warmer than 

 the vagina of the mother, viz., 37*86. A short time after birth, the temperature 

 falls 0*9, while twelve to twenty-four hours afterwards, it has risen to the normal 

 temperature of an infant, which is 37*45. Several irregular variations occur 

 during the first weeks of life. During sleep, the temperature of an infant falls 

 0*34 to 0*56, while continued crying may raise it several tenths of a degree. 

 Old people, on account of their feeble metabolism, produce little heat ; they 

 become cold sooner, and hence ought to wear warm clothing to keep up their 

 temperature. 



(4) Periodical Daily Variations. In the course of twenty-four hours there are 

 regular periodic variations in the mean temperature, and these occur at all ages. 

 As a general rule, the temperature continues to rise during the day (maximum at 

 5 to 8 p.m.), while it continues to fall during the night (minimum 2 to 6 a.m.). 

 The mean temperature occurs at the third hour after breakfast. 



