# Sauna basics: types, what heat does and how to behave

Source: https://saunabenefits.uk/basics/
Author: Kit Ellery · Updated 2026-11-04

**Short answer:** A sauna is a small room heated to between about 70°C and 100°C, usually with low humidity, that you sit in for a few minutes at a time to make your body heat up and sweat. Infrared cabins run cooler, and steam rooms are cooler but saturated with moisture. Most health research used traditional Finnish saunas.

## What counts as a sauna?

The word comes from Finland, where saunas have been part of everyday life for centuries and there are around two million of them for five and a half million people. A traditional Finnish sauna is a wood-lined room with benches and a stove topped with stones. The stove heats the air to roughly 70°C to 100°C. Humidity stays low, around 10% to 20%, except for the short bursts of steam when you ladle water onto the stones.

Other heat baths work differently. [Types of sauna](/basics/types-of-sauna/) compares the Finnish sauna, the Russian banya, the infrared cabin, the steam room and the hot tub side by side.

## Why does the type matter for health?

Because nearly all the long-term research, including the Finnish studies on [heart health](/benefits/heart-health/) and [blood pressure](/benefits/blood-pressure/), looked at people using traditional saunas at around 80°C. Infrared cabins and steam rooms heat your body more gently or in a different way, and we can't assume the same results apply. [Infrared vs traditional](/basics/infrared-vs-traditional-sauna/) goes through what is known.

## What happens to your body in a sauna?

Your skin warms to around 40°C, your core temperature rises by about a degree, your heart speeds up and blood vessels in your skin widen. You sweat, often around half a kilo in a session. Afterwards, blood pressure dips for a while. [What a sauna does to your body](/basics/what-a-sauna-does-to-your-body/) explains each stage and why it matters.

## Where can you use one in the UK?

Gyms, leisure centres and spas have long had small saunas. Since about 2023, a wave of standalone public saunas and sauna clubs has opened across the UK, many on beaches, harbours, rivers and lakes, where you can follow the heat with a cold-water dip. Each has its own customs: [public sauna etiquette](/basics/sauna-etiquette/) covers the basics so you know what to expect.

## Frequently asked questions

### What is the difference between a sauna and a steam room?

A traditional sauna is hot and fairly dry, typically 70°C to 100°C with 10% to 20% humidity, rising briefly when water is thrown on the stones. A steam room is much cooler, about 40°C to 50°C, but close to 100% humidity, so sweat can't evaporate.

### What is löyly?

Löyly is the Finnish word for the steam that rises when you throw water on the hot sauna stones, and for the wave of heat you feel as it reaches you.

### Do you wear clothes in a UK sauna?

In most UK public saunas, swimwear is expected. Some spas and sauna clubs, especially those run in the German or Finnish style, have textile-free sessions. Check the venue's rules.

## References

1. [Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and other health benefits of sauna bathing: a review of the evidence. Mayo Clinic Proceedings, 2018.](https://pubmed.ncbi.nlm.nih.gov/30077204/)
2. [Heinonen I, Laukkanen JA. Effects of heat and cold on health, with special reference to Finnish sauna bathing. American Journal of Physiology, 2018.](https://pubmed.ncbi.nlm.nih.gov/29351426/)
3. [Kenttämies A, Karkola K. Death in sauna. Journal of Forensic Sciences, 2008.](https://pubmed.ncbi.nlm.nih.gov/18471223/)