By immersing your body in chilled water, the sudden cold sets off a reaction in the limbic (ancient) area in the base of your brain that is programmed to respond to such dramatic external events, in this case, it senses that you might be freezing dangerously. This is also called the ‘fight-or-flight’ response.

Additionally this response to ‘environmental stress’ conditions our brain to cope better with the stressors of everyday life and helps decrease the production of inflammatory cytokines which are linked to anxiety and depression.