The sole of the foot is the main part of the whole organ, especially the brain, followed by the kidney. Therefore, if you stay healthy and help you sleep, you'd better stick to soaking your feet in hot water 15 to 20 minutes every day, so that your body and sleep will be better. Moreover, I suggest that you drink a glass of milk before going to bed every day, which will help you sleep better. Finally, I wish you good health and a happy life.