The temperature should not be too high, the water temperature should be controlled at about 30 degrees. Because too high a temperature will increase the local metabolism and oxygen consumption, and ischemic patients can not meet this demand, so it will make the local ischemia more serious and aggravate the burden on the blood vessels, thus causing damage to the blood vessels. The immersion time should not be too long, about 30 minutes is appropriate. Too long a time does not increase the therapeutic effect, but will affect the blood circulation of the lower limbs due to the prolonged sagging of the limbs. After immersion, the lower limbs should be washed with water, and patients with traumas should change the medication in time after immersion. After soaking the limbs should pay attention to heat preservation, do not make the lower limbs or feet exposed to the outside for a long time.