This study was to determine the effect of cooling parts of the limbs without harm to health. The results provide basic data for the development of clothing which could increase work efficiency and reduce body strain in hot environments. Five male adults took part in the study, conducted in a climate chamber with an ambient temperature of $37^{circ}C$ and a relative humidity of 50%. The limbs were divided into six areas to be cooled: upper arm, forearm, thigh, calf, hand, and foot. According to preceding studies, permissible cooling safety limits of skin temperature for each part of the body for one-hour were $20^{circ}C$ on the upper arm, forearm, thigh, and calf, and $23^{circ}C$ on the hand and foot. For this reason, cooling the skin of each region was carried out at the above mentioned temperatures. In conclusion, cooling the hand and foot reduced perspiration, rectal temperature and heart rate. Therefore, the heat stress of workers exposed to hot environments would be reduced by decreased subjective sensations of heat and increased comfort. The effectiveness of cooling was better on the arm than on the leg.