What sauna and cold exposure involve
These protocols use deliberate heat (traditional sauna) and cold (cold showers, cold-water immersion) exposure, often in alternation, as mild stressors intended to trigger beneficial adaptations.
Evidence and what to consider
Observational research has linked frequent sauna use to lower cardiovascular and all-cause mortality in a dose-dependent way, although this isn't proven to be causal. Evidence for cold exposure is more preliminary, based largely on soft endpoints and mechanisms. Both are generally low-cost and accessible; people with cardiovascular conditions or who are pregnant should check with a doctor, as heat and cold can stress the heart.
