The purpose of this study was to investigate the influences of foot baths in cold water (cold baths) on thermoregulatory function and autonomic nervous activities in a heat environment (34℃, 70% RH). Fifteen healthy women in their twenties were given a 15-minute cold bath at 15℃, and measurements were taken for oral temperature, skin temperature, finger skin blood flow, sweat rate on the back and heart rate. The results were as follows: Oral temperature decreased significantly during and after the cold bath (p < 0.01). The skin temperatures for different parts of the cold bath group were lower than the control group during the cold bath. At the same time, the skin temperatures of all parts of the cold bath group were lower than those before the cold bath, and the order of temperature drop was (from highest to lowest): foot, toe, lower leg, finger, chest, thigh, forehead, upper arm. After the cold bath, the skin temperature of the chest, thigh, foot and toe recovered, while the forehead, finger and lower leg did not. The mean skin temperature decreased significantly during the cold bath, but increased significantly afterward. Finger skin blood flow and dorsal sweat rate decreased in the cold bath, but slightly increased afterward. R-R interval and HF continued to increase from the beginning to the end of the cold bath, which promoted parasympathetic activity and reflected a relaxation effect.