IFMC. Hot spring socks have been created with a focus on hot spring therapy, and have been realized to keep your feet feeling comfortable. By putting it close to the body, nitrogen monoxide (NO) spreads from the blood vessel, and you can expect to increase blood circulation by expanding the blood vessels. Used by professional baseball players and many athletes, the research has been progressed in the Kyoto Universitys Institute of Life Science and High Definition Biological Science categories.