[jks]

There used to be a Finnish sauna endurance competition where the temperature was 110℃. It was canceled in 2010 after one contestant died.

https://en.wikipedia.org/wiki/World_Sauna_Championships

[MobiusHorizons]

This is a big sauna, most of the air is not at that temperature. And I would certainly not attempt endurance in it, but the thermometer on the wall usually is between 235F and 245F