The time of foot soaking varies slightly according to individual constitution, age, etc., usually about 15-20 minutes is appropriate. Generally used for wind-cold external sensations, and the water temperature should not be too high, in order to sweat to the extent that the fruit of the water temperature is too high, then the blood flow in the lower extremities increased, which will lead to overloading of the heart, easy to cause vasodilatation. In addition, if the water temperature is too high, it may trigger the whole body to discharge more sweat, resulting in the disappearance of some trace elements and minerals in the body, resulting in weakness, fatigue, panic and shortness of breath and other symptoms. It is recommended that the water temperature is maintained at about 38-40 degrees, soak to the back slightly sweaty, forehead slightly sweating can be. As the 64 reflex zones on the soles of the feet correspond to the five viscera and six bowels, 7-9 p.m. kidney meridian qi and blood is the weakest, at this time, soaking the feet can replenish the qi and blood, and half an hour after dinner to avoid soaking the feet, otherwise the blood flowing to the digestive system will flow to the lower extremities, resulting in dyspepsia. In addition, foot soaking can reduce high blood pressure, heart disease and stroke and other high-risk diseases, but heart disease, cardiac insufficiency, low blood pressure should not use hot water to soak their feet.