THE EFFECT OF RATE OF HEATING AND ENVIRONMENTAL TEMPERATURE ON PANTING THRESHOLD TEMPERATURES OF NORMAL DOGS HEATED BY DIATHERMY

Abstract

Trained normal dogs were heated with measured dosages of diathermy heat in (1) an environment of constant temp. and with variation of the rate of heating and (2) with constant rate of heating, 1.0 b. m. r. heating rate, in environments which varied from 22 to 28[degree]. Skin temp. were measured by thermocouples from 11 places on the body surface. The skin and rectal temps. were measured after a 21/2 hr. rest and when panting commenced. The most reactive skin temp. was the ear temp., which increased from the lowest of the skin temps. to the highest as a result of heating, indicating the importance of the ears in heat loss. Panting induced by diathermy is probably "peripheral reflex panting" rather than "central panting." The skin threshold temps. at which panting started did not depend on the rate of heating but were reduced by lowering the environmental temp.