What is sauna?

Broadly, sauna is a form of passive heat therapy in which individuals sit in small, high-temperature rooms for short periods of time. The specific design and practices of using the sauna vary considerably, but the majority of research has been on traditional Finnish sauna, which is characterized by:^[1]

• Rooms made of wood and heated by hot rocks
• Temperature and humidity ranges of 90–100°C (170–212℉) and 10%–20%, respectively
• Durations of 5–20 minutes, although some go longer
• Cooling-off periods in which bathers swim, shower, or roll in snow
• A frequency of 2–3 times each week