You know, the feet are far from the heart, the branches of blood vessels are the farthest, and the subcutaneous fat layer is very thin. In addition, the cold invasion in winter reduces people's activity, resulting in poor blood flow to the feet, insufficient blood supply, and the metabolites can not be excreted in time. If you iron your feet before going to bed every night, you can effectively promote local blood circulation, increase the nutrient supply of waste, keep your skin soft, remove the nutrient supply of waste, keep your skin soft, and relieve the heaviness of lower limbs and general fatigue. At the same time, hot water is also a good stimulus to the cerebral cortex, which is conducive to promoting sleep. In addition, hot water scalding feet can also prevent foot frostbite and skin cracking. Therefore, as the saying goes, "It's better to take tonic if you burn your feet before going to bed."