A traditional sauna (often called Finnish sauna) is a form of passive heat therapy involving exposure to high environmental temperatures, typically 80–100°C (176–212°F), with low humidity (10–20%) in a wooden room heated by a stove or heater, often with rocks that can be splashed with water to create brief bursts of steam. Sessions usually last 5–20 minutes, promoting intense sweating, elevated heart rate, and physiological responses akin to moderate exercise.

Scientific evidence, primarily from large prospective cohort studies (e.g., Kuopio Ischemic Heart Disease Risk Factor Study) and systematic reviews, supports several benefits of regular traditional sauna use (2–7 times/week), though more randomized trials are needed:

• Cardiovascular health: Strongly linked to reduced risk of fatal cardiovascular events, including sudden cardiac death (up to 63% lower with 4–7 sessions/week), coronary heart disease, stroke, hypertension, and overall CVD mortality. It improves endothelial function, reduces arterial stiffness, lowers blood pressure, enhances circulation, and mimics exercise-like effects on the heart and vessels.

• All-cause mortality: Associated with lower overall death risk in a dose-dependent manner.

• Other effects: Potential reductions in dementia/Alzheimer’s risk (up to 66% lower with frequent use), respiratory conditions (e.g., pneumonia, chronic lung diseases), inflammation markers, and improved mental well-being/stress reduction via autonomic and neuroendocrine changes.

These benefits stem from heat-induced vasodilation, increased nitric oxide, anti-inflammatory effects, and hormetic stress responses.