688 



ANIMAL HEAT 



325 

 38 



425 



cular exercise is capable of causing a considerable rise in the tem- 

 perature of the rectum and urine, to 38*5 C. (101-3 F.) or even 

 38-9 C. (102 F.) without producing any feeling of distress. Other 

 unknown influences seern also to be involved, as is shown by the 

 fact that in persons who work at night and sleep during the day 

 the curve of temperature, although greatly altered, is not reversed. 

 Recent observations on this subject are those of Benedict. By 

 means of a resistance thermometer in the rectum, readings were 



taken usually every four minutes. 

 With such a thermometer no disturb- 

 ance of the person's sleep is necessary 

 to obtain a reading. He can sit with- 

 out discomfort in any position, walk 

 about the room (returning to the ob- 

 server's table for the observations), 

 and even ride a stationary bicycle 

 Even years of night- work do not elim- 

 inate the tendency to a fall of tempera- 

 ture at night, a minimum in the early 

 morning, and a morning rise. 



As to the relation of age and sex to 

 temperature, it is only necessary to 

 remark that the mean temperature 

 both of the young child and of the 

 old man is somewhat higher than 

 that of the vigorous adult; but a 

 point of more importance is the rela- 

 tive imperfection of the heat-regulation 

 in infancy and age, and the greater 

 effect of accidental circumstances on 

 the mean temperature. Thus, old people and young children are 

 specially liable to chills, and a fit of crying may be sufficient to 

 send up the temperature of a baby. In infants an hour or two old 

 the temperature may be as low as 34 C. (93'2 F.) or 33-0 C 

 (91-4 F.) even when they are fully clothed in a room at 15 C. 

 (59 F.). It rises gradually during the first day or two, but shows 

 marked variations. On the fifth day after birth, e.g., the rectal 

 temperature ranged from 36-2 C. (97-16 F.) to 33-5 C. (92-3 F.) 

 in a child weighing 5^ pounds (Babak). The temperature of women 

 is generally a little higher than that of men, and is also somewhat 

 more variable. A fall of temperature, rarely amounting to more 

 than i F., is associated with the menstrual period. 



After death the body cools at first rapidly, then more slowly 

 (Fig. 217). But occasionally a post-mortem rise of temperature 

 may take place. In certain acute diseases (like tetanus) associated 

 with excessive muscular contraction this has been especially noticed ; 

 in bodies wasted by prolonged illness it does not occur. Nearly an 



28 



Fig. 217. Curve of Cooling after 

 Death : Guinea - Pig. Time 

 marked along horizontal, and 

 temperature along vertical axis. 

 At a ether and chloroform 

 given to kill animal; death, as 

 indicated by stoppage of the 

 heart, took place at b. The 

 dotted line shows the course 

 the curve would have taken if 

 death had occurred at th 

 moment the anaesthetics were 

 given. Air of room 17 '6. 



