Dry Finnish saunas have 10-20% relative humidity, while wet saunas have ~100% relative humidity and cannot exceed 115°F without burns.

“Dry finished saunas as the name would suggest are pretty dry. They have a relative humidity of 10 to 20%. Whereas a normal room temperature has about 30 to 50% relative humidity, but that can be a lot lower in the winter. West saunas have roughly 100% relative humidity. That means they can't get above 115 Fahrenheit, 46 C without causing you to burn or overheat.”

“Dry finished saunas as the name would suggest are pretty dry. They have a relative humidity of 10 to 20%. Whereas a normal room temperature has about 30 to 50% relative humidity, but that can be a lot lower in the winter. West saunas have roughly 100% relative humidity. That means they can't get above 115 Fahrenheit, 46 C without causing you to burn or overheat. And as we know, most of the evidence for sauna's health benefits, especially long-term cardiovascular studies, focuses on finished sauna, where the combination of high heat and low humidity places the body under significant thermal and cardiovascular stress.”

“The standard sauna practice involves temperatures of around 175°F with a humidity level ranging from 10-20%, and sessions typically last 20 minutes or more.”