It requires little analysis to discern that the temperature of an object represents the resultant of two factors: the gain of heat from without or within and the loss of heat. The body temperature of an animal may therefore be conceived to represent a balance between heat production and heat dissipation. In some organisms which we term cold-blooded animals, like the frog, the temperature of the body is ordinarily only slightly higher, at most, than that of their environment. Among the so-called warm-blooded animals, including man, on the other hand, the balance is so adjusted that it remains fairly constant for the individuals and the species, despite wide variations in the temperature of their surroundings.
To account for this unique regulatory phenomenon it has become popular within recent years to assume the existence of a special "center" which acts analogously to a thermoregulator. To recall the various precise locations of
THE REGULATION OF BODY TEMPERATURE. JAMA. 1918;71(14):1139–1140. doi:10.1001/jama.1918.02600400039014