Not at all. Most any sauna worth the name operates at 65-70℃ at the absolute low end, and typically sits at 80-90℃ at ideal operating temperatures.

Then you go an splash an entire ladle of water over the rocks and feel the scorching heat wash over you.

Invigorating.

Nah, not that crazy… typically a sauna here, in Sweden, is between 70 - 100 C.