Contrast baths are used for ankle, foot, or hand problems to help decrease inflammation and pain. They involve dipping the injured limb alternately into cold and warm (not hot) water.
Starting about 48 hours after an injury, the affected limb is submerged in a bucket of ice-cold water (as cold as can be tolerated) for about 2 minutes.
The limb is then moved into a second bucket filled with lukewarm (not hot) water, around 104°F (40°C), for 30 seconds.
The soaks are alternated for a total of up to 15 minutes, with the first and last soak in cold water. Ideally, the baths are repeated 3 times a day.
It is important to end a contrast bath with a soak in cold water to help reduce swelling.
These baths can be continued at least daily for up to 2 weeks. But if swelling and bruising last this long, a doctor should be consulted.
There is not much evidence that contrast baths work better than ice, but the theory is that changing the temperature back and forth between cold and warm creates a kind of pump. Heat causes blood vessels to get bigger and cold causes them to get smaller. Alternating between heat and cold means the blood vessels alternate between bigger and smaller. This change in blood movement could help reduce inflammation and swelling, and that could improve range of motion in the joint.