EMPLOYMENT OF HEAT. 407 



attending the febrile process cannot be dependent upon the elevation of 

 temperature, but must be brought about by the inadequate nutritive 

 state of the tissues, or by bacterial poisons. Fever may also endanger 

 life through elevation of the bodily temperature. If the temperature re- 

 mains at 42.5 C. for a considerable time death is unavoidable. If the 

 artificial elevation of temperature is not increased to the point of causing 

 death, beginning in from thirty-six to forty-eight hours fatty infiltration 

 and degeneration will take place in the liver, the heart, the kidneys and 

 the muscles. 



In cold-blooded animals the temperature can be raised from 6 to 10 C. 

 within a short time, by exposure to hot water as well as to hot air. As the heart 

 of the frog ceases to beat at a temperature of 40, and as the muscles in the interior 

 of the body begin to become rigid at the same temperature, the maximum tempera- 

 ture for the continuance of Hfe is in this animal considerably lower. Actual 

 death is preceded by a condition of apparent death, from which resuscitation is 

 possible. Insects live in the desert at a temperature of 64 R. and arctisca and 

 anguillulae die in water at a temperature of 45, while in a dry medium they can 

 be heated to a temperature of 70, and rotifers, after careful desiccation, can be 

 heated to 125 C. Most juicy plants die after exposure for half an hour to air 

 at a temperature of 52 C. or to water at a temperature of 46 C. Desiccated 

 seeds (oats) may retain their germinating activity after exposure for a considerable 

 time to air at a temperature of 120 C. Lowly organized plants, such as the 

 algse, can live in warm springs at temperatures up to 60 C. Some bacteria 

 tolerate the boiling temperature. 



EMPLOYMENT OF HEAT. 



Brief and not intense heat applied to the surface of the body causes at first 

 a transitory, slight reduction in the bodily temperature, partly because the pro- 

 duction of heat is thereby diminished through reflex influences, partly because 

 more heat is given off in consequence of dilatation of the cutaneous vessels and 

 expansion of the skin. Baths at a temperature above that of the blood cause at 

 once elevation of the bodily temperature. Following the bath a slight reduction 

 in temperature takes place after a time. Apart from the changes in bodily tem- 

 perature brought about by changes in circulation and in respiration, Oppenheimer 

 estimates the elevation of temperature, t, brought about by a bath of 400 liters 

 (kilos) at a temperature of 40 C. and of half an hour's duration (the time required 

 to warm the body thoroughly), in a man weighing 75 kilos, with a bodily tem- 

 perature of 37 C., assuming equal heat-capacity for the body and the water of 

 the bath : 



(400 + 75) t = 400.40 + 75,37; therefore t = * !/ _ = 39.5. 



The temperature of the body, thus, rises from 37 to 39.5 C., an increase of 2.5 

 C., representing 187,500 heat-units. 



General application of heat to the entire body is indicated when the bodily 

 temperature has fallen extremely low, or when danger is threatened thereby, as 

 in the algid stage of cholera, and in the case of a premature human fetus. General 

 supply of heat is effected by means of warm baths, packs (beds) , vapors, insolation, 

 and copious hot drinks. Heat is applied locally by means of hot compresses, 

 partial baths, placing of a part in hot earth or sand, introduction of a part into 

 the body of a recently killed animal (animal bath) , introduction of injured parts 

 into receptacles containing heated air. After removal of the heating agent, the 

 greater amount of heat-dissipation caused by the dilatation of the vessels is to be 

 taken into consideration. 



POST-MORTEM ELEVATION OF TEMPERATURE. 



R. Heidenhain found as a constant phenomenon in dogs that were killed that 

 a transitory elevation of temperature took place before the cooling of the cadaver 

 set in, and this slightly exceeded the normal temperature of the body. 

 Similar, and in part remarkable, elevations of temperature had been observed 



