The Effect of the Different Environmental Temperatures on the Basal Heat Production (Report III)

Abstract

In this report as a series of previous experiments (Report 1 and 2), experimental environmental temperatures were set at the range from 40°C to -20°C and the effects of these different temperatures on the basal heat production were studied by the same methods and experimental conditions as described in previous reports. And more, in this experiment the following method was attempted, i. e., subject's head was placed in the room kept at lower temperature (0°C or -16°C) and his body was placed in the comfortable room, instead of keeping the subject at warmly conditions in lower environmental temperatures by varying the clothing conditions.Results obtained were as follows.1) The heat productions at higher 40°C in this experiment did not show any signifcant variation above the basal metabolism, though the rising metabolism was seen, at the corresponding temperatures in previous summer and autumn experiments. And also, the rising metabolism at lower 10°C and -20°C temperatures in winter was lower than the heat production at 10°C and -15°C in autumn experiment. These inclination suggest that one's physiological status in winter has much tolerance or adaptability to the wide range from higher to lower environmental temperatures.2) The basal heat production showed no signifcant variation when the head was placed in the room kept at 0°C or -16°C and the body was layed at comfortable room.This data show theoretically that there is no variation in the basal metabolism even at cosiderable lower environmental temperature such as -16°C, if the body is completely kept at comfortable temperature.3) The skin temperature measured at lower temperature in this experiment showed the tendency of smaller variation at the sole and hand, as compared with the previous experiments in summer and autumn.