Bradley Cooper says he dives into a frozen pool "every morning when I get up" Ice water immersion is a practice of cold therapy that involves full or partial immersion in water below 50 degrees Celsius for a short period of time. Immersion in an ice bath is said to improve muscle recovery by inducing "a state of vasoconstriction, where blood vessels constrict rapidly to redirect blood flow to major organs" The Wim Hof Method, created by Dutch extreme athlete Wim Hof, also employed cold therapy as a way to increase focus, increase energy and reduce stress.