Abstract
The effects of trunk-and extremity-cooling on the regional differences in thermoregulatory responses have been studied by using a separated water-perf used suit. Eight women subjects have been kept in the rest supine posture in a climatic chamber of 30.0±0.5°C in temperature, 50±3% in relative humidity, and 0.2m/sec. in air velocity. Investigations have been made two times under trunk-cooling and extremity-cooling conditions separately. A suit set temperature was initially maintained at 33°C for 30 min. and then lowered to 24°C by every 3°C for every 30min. The skin temperatures in chest, back, finger and toe decreased significantly, but those in upper arm, thigh, and leg increased significantly (p<0.05) during trunk-cooling for ninety minutes. On the other hand, only chest skin temperature rose significantly and other skin temperatures fell significantly (p<0.05) during extremity-cooling. But the chest skin blood flow in both cooling conditions increased beyond those at 0 min and 33°C. In spite of the no cooling region, the finger blood flow and the skin temperature decreased beyond those at 0 min and 33°C in both cooling conditions. The skin temperature and skin blood flow of the finger in extremity-cooling were lower than those of trunk-cooling condition. In addition, the extremity-cooling of thermal and comfort sensations were cooler and more uncomfortable that those of trunk-cooling. These results suggest that the extremity-cooling will greatly affect on thermoregulatory responses than the trunk-cooling.
