What happens to the body during cold exposure and is it actually beneficial?

The answer

Cold exposure triggers measurable physiological responses with potential health benefits. When skin temperature drops below 15°C, the sympathetic nervous system releases norepinephrine - up to 200-300% above baseline after cold water immersion - reducing inflammation and improving mood. Brown adipose tissue (BAT), activated by cold, burns calories to generate heat: regular cold exposure can increase BAT volume and metabolic rate by 10-15%. A 2016 Dutch study of 3,018 participants found that routine cold showers reduced sick days by 29%. Wim Hof demonstrated conscious influence over his immune system in a landmark 2014 study at Radboud University, where his breathing technique enabled healthy volunteers to suppress cytokine responses to endotoxin injection by 50% - previously thought impossible through voluntary means.