A STUDY OF THE AVERAGE TEMPERATURE OF THE TISSUES, OF THE EXCHANGES OF HEAT AND VASOMOTOR RESPONSES IN MAN BY MEANS OF A BATH CALORIMETER

Publisher Website
Google Scholar
Abstract
An insulated bathtub, stirred and electrically heated, was used to measure the heat loss from the immersed body. In 20 min. periods the accuracy was [plus or minus]4%. Reflex vasomotor adjustments of the effective thermal conductivity of the tissues, which may change by a factor of 6 times, keep the heat loss constant in baths from 1[degree]C to 4[degree]C lower than rectal temp. Colder baths induce increased metabolism which is accompanied by an increase in the conductivity. The response to lowering the bath temp. is usually an initial rise of rectal temp. and vice versa, and mathematical analysis on a model shows that these changes are to be expected from reflex vasomotor changes in conductivity. Evidence is given suggesting a seasonal change in conductivity, probably associated with changes in blood volume. Vasodilation from CO2 inhalation and nitroglycerine, and constriction from hyperpnoea were evident in the calorimetry. When the surface temperature is changed by more than 1.5[degree]C the rectal temp. is inadequate to give the direction or magnitude of the change in average body temp.

This publication has 4 references indexed in Scilit: