If the water temperature is too high, it should be controlled at 40-50℃. If it is low, it will have no effect, but if it is high, it will affect the skin. For too long, the feet are soaked in the water of Artemisia argyi for a long time, because the external osmotic pressure increases, the cells are dehydrated, the terminal microvascular atresia, and the epidermis falls off, which will cause itching. In fact, this is a physiological phenomenon; Control it for about 30 minutes.