Contrast hydrotherapy is the use of alternating hot and cold water to boost the immune system and improve circulation. Contrast showers are an example of this. After taking a hot shower, step out from under the water, turn it to a cool temperature, and then rinse each limb under water, one at a time for about 5-10 seconds each. While it sounds crazy to end your shower with cool water in the winter, it provides many benefits. It causes the blood vessels to go from dilated to constricted which naturally stimulates circulation. If showers are ended with warm water, the blood vessels are left dilated to release heat, which actually makes the body colder after the shower. However if ending with cold water, the vessels constrict and shunt blood to the core of the body therefore keeping the body warmer. The improved circulation also supports immune boosting properties and leaves people with a great energy burst!