A COMPARATIVE STUDY OF TEMPERATURE FLUCTUATIONS IN 

 DIFFERENT PARTS OF THE HUMAN BODY. 



Part I. Introduction. 



The normal body-temperature is a resultant of two factors, thermogenesis, 

 or the development of heat inside the body; and thermolysis, the loss of heat 

 from the body. Usually these two factors are so delicately adjusted as to be 

 nearly equal in value and hence the resulting temperature of the body does 

 not alter materially. When there are marked disturbances in either factor, 

 we have changes in body-temperature. Innumerable experiments 1 have been 

 made to investigate the factors influencing both thermogenesis and thermolysis, 

 and it has been proved that the most important factor affecting thermogenesis 

 is muscular work, either voluntary or involuntary, while the most important 

 factor affecting thermolysis is the temperature environment; this latter is 

 particularly true of small animals. 



A knowledge of the fluctuations in body-temperature is of inestimable value 

 to the physician as an index of the body condition; in health the normal limits 

 are rarely exceeded, and consequently increased temperature indicates that 

 radical measures must be taken. To the physiologist, also, a knowledge of the 

 course of the normal body-temperature is important, and when experiments 

 on calorimetry are attempted this factor has especial significance. 



HEAT PRODUCTION. 



By means of modern apparatus, an accurate measurement may now be made 

 of the total heat given off from the body of a man during an experimental 

 period by the three paths of conduction, radiation, and the latent heat of 

 water vaporized. This of itself is an important contribution to physiology, 

 but of still greater importance is the measurement of the total heat production. 

 The heat production may or may not be the same as the heat elimination, 

 since any discrepancy between thermogenesis and thermolysis causes a change 

 in body-temperature resulting in the loss of a certain amount of heat previously 

 stored, or the storage of heat to be subsequently eliminated. This may be 

 shown by a simple calculation: 



From the results of a large number of experiments, a standard value for 

 heat production has been computed for a man weighing G6.6 kilograms, while 

 at rest and asleep. 2 Owing to its large content of water, the body has the 



A historical development, of the study of body-temperature, including methods, is given 

 in the excellent article by Pembrey in Schaefer's Textbook of Physiology, vol. 1, 1898, p. 

 785. This article also includes an extensive statement of literature up to the date of 

 publication. 



-Benedict and Carpenter, Pub. No. 126, Carnegie Institution of Washington, 1910, p. 253. 



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