1106 ANIMAL HEAT 



of its cutaneous blood-vessels. ^ If placed in a warm chamber or covered with 

 straw or blankets, it invariably survives the critical period directly after the appli- 

 cation of the varnish, because later on the hairs grow out sufficiently to disengage 

 the varnish from the skin, allowing the latter at least partially to protect itself 

 against this enforced loss of heat. The view that this procedure prevents the 

 elimination of toxic substances through the skin, has not found experimental 

 substantiation. The administration of nervous depressants most generally evokes 

 a loss of heat against which the patient must be carefully guarded. Thus, extra 

 blankets are to be placed upon a person who has been given chloral. 



Hjrperthermy and Hjrpothermy. — In addition to the variations in 

 the body-temperature noted in the course of the previous discussion, 

 brief reference should also be made at this time to the hyperthermy 

 commonly following the entrance into the body of pathogenic bacteria 

 and toxic substances, such as the derivatives of fermentative processes. 

 This condition which is usually designated as fever, is represented by 

 a complex of symptoms of which a decided and rather lasting elevation 

 of the body-temperature is the most characteristic. Rises to 38° or 

 39° C. are usually spoken of as ''low fever " or pyrexia, and rises to 41° C. 

 as ''high fever" or hyperpyrexia. Among the other readily recog- 

 nizable signs are thirst, painful sensations, weakness, apathy, nausea, 

 vomiting, alterations in the quantity and quality of the various secre- 

 tions and excretions of the body, and such other changes as may be more 

 specifically related to the infection. Fever may begin gradually, and 

 more abruptly with a chill; it may be constant, remittent and intermit- 

 tent; it may last a variable period of time and disappear either gradu- 

 ally or rather suddenly. In every case, however, it represents a physi- 

 ological attempt on the part of the body to correct a disturbance of 

 function, and hence, it is quite proper to refer to it as a reaction. 



Fever or pyrexia may be due either to an increased production or 

 to a diminished dissipation of heat, or both. Evidently, any dispropor- 

 tionality between these two factors which leaves a positive balance for 

 heat, must bring about an elevation of the body-temperature. Con- 

 cerning the first factor, we have the positive statements of Krauss,- 

 Nebelthau,^ May,^ Staehelm,^ and others that thermogenesis is in- 

 creased during fever, the difference amounting to as much as 25 to 50 

 per cent. Direct calorimetric determinations have also proved that 

 the loss of heat is increased during fever, but in comparison with the 

 the enormous production of heat, the dissipation is undoubtedly dimin- 

 ished. In other words, the heat is stagnated, as is evinced by the 

 livid, blue and cold character of the skin following the contraction of 

 the cutaneous blood-vessels and the cessation of evaporation from the 

 skin. When these changes first occur, a sensation of cold is experi- 

 enced which causes the patient to draw his body into as small a mass as 

 possible and to cover himself thickly with blankets. The quivering 



1 Krieger, Zeitschr. fur Biol., 1869; also Babak, Pfluger's Archiv, cviii, 1905, 389. 



2 Zeitschr. ftir khn. Med., xviii, 1890, 91. 



3 Zeitschr. fiir Biol., xxxi, 1894, 293. 

 ^ Ibid., XXX, 1893. 



5 Zeitschr. fiir klin. Med., Ixvi, 1904, 77. 



