The objects of this study were to investigate responses and peculiarity during local cooling by parts of the human body and to show permissible safety limits without injurious to his health because of excessive cooling when he works hot environments. It were measured rectal temperature, skin temperature, heart rate, total body weight loss, local sweat in back and thigh, clothing microclimate and subjective sensation on 8 subjects and cooling parts were head, neck, chest, abdomen, back, waist, hip, upper arm, forearm, hand, thigh, calf and foot. According to above-mentioned the first experiment, we chose permissible safety limits by parts of the human body for one hour. In the second experiment, it was showed permissible safety limits by parts which examined their safety about health through 4 hours cooling test on 3 subjects. The results are as follows: 1. As a result of the first experiment, we chose permissible safety limits by parts, as follows, head $25^{\circ}C$, neck $20^{\circ}C$, chest $27^{\circ}C$, abdomen $25^{\circ}C$, back $20^{\circ}C$, waist $20^{\circ}C$, upper arm $20^{\circ}C$, forearm $20^{\circ}C$, hand $23^{\circ}C$, thigh $20^{\circ}C$, calf $20^{\circ}C$ and foot $23^{\circ}C$ in $37^{\circ}C$, 50%R.H. environment for 1 hour. 2. As a result of the second experiment, cooling on these safety limits temperatures except chest didn't have a bad effect on health. So it was proved that right permissible safety limits of chest was $28^{\circ}C$. From these results, it has been suggested that skin temperature didn't fall below permissible safety limits when human body was to be cool by parts.