If you pass your foot warm through warm water, the blood circulation will be improved and your body will get warm. If your body gets warm, you will feel comfortable owing to the vigorous activities of autonomic nervous system governing visceral function and in vivo enzymes, and the improved physiologic function. The health care method like this which makes our body comfortable by warming foot is called as "Leg Spa."  The blood enables activity and growth of human body by supplying oxygen and nutrients and eliminating waste matters, and keeps body temperature. Therefore, if whole body gets warmness through smooth blood circulation, then the entire regulatory functions of living body, that is, the homeostasis (the function always maintaining body condition steadily), will be improved.