Cryosaunas use nitrogen to lower your skin surface temperature by 30 to 50 degrees Fahrenheit over a period of three minutes. The skin reacts to the cold and sends messages to the brain that acts as a stimulant to the regulatory function of the body. As your body is exposed to the cold, the veins on the exterior regions of your body begin to constrict, causing blood to rush into your body's core, where the blood becomes super oxygenated. Once you are removed from the chamber your blood vessels expand allowing newly rejuvenated blood to rush back to your extremeties and skin.