沖縄在住者の耐熱・耐寒性に関する研究

抄録

This study has been tried to analyse the mechanism of environmental assimilation of human body to the subtropical climate condition from the evaluation of heat and cold tolerances in the Okinawan residents exposing constantly to a high temperature throughout the year. Twelve healthy male adults immigrating to the Okinawan district from the mainland of Japan were selected for this study with the same number of controls natively residing in Okinawa. The load of 30°C, 70% humidity for 60 minutes with the continuous recording of body surface temperatures and the detection of metabolic rates at 0, 30 and 60 minutes, and, the load of 10°C, 70% humidity for 60 minutes with the measurement of sweating volume and sodium concentration was carried on the individuals in each group. The mean body surface temperature was gradually descended after the start of cold exposure in both group, however, the depletion was relatively steep in the mainland group. The amount of heat exsudation caliculating as a metabolic rate was gradually increased with the progress of cold exposure in both group, however, the increasing tendency of those was more prominent in the Okinawan group. The amount of sweating volume obtained during the heat exposure with the decrease of body weight exceeding in the mainland group was recognized with the high rate of sodium excretion in comparison with those in the Okinawan group. These data suggested that the individuals of mainland group is more compatible t o the cold tolerance with the less heat tolerance capacity residing in subtropical area, however, no definite indication of environmental assimilation to high temperature in the mainland group is confirmed during this short experiment.