Careful there, Mike. Them things are dangerous!
My friend in Hope built one 10X12, concrete floor, no floor drain, many years ago, out of either 6 or 8 inch , 3-sided squared cedar. Don't ask where he got it... but he was working for a government agency at the time, and they had some leftovers.
The wife and I were over visiting and he fired up the sauna. True, we'd been into the banana Daiquiris for awhile... and I'd never been in a sauna before.
I was advised that if I started feeling weak I should go outside (it was down around zero) where there was a half barrel filled with cold water, and douse myself over the head until I recovered and could re-enter. "The pitcher is right there"....
So it came to pass. No one told me his wife had brought out the pitcher of Daiquiris as well... I just thought someone had thoughtfully pre-filled that pitcher. It took another half dozen pitchers of cold water to get all that stuff out of my hair.
I not only remember it well, I'm frequently reminded of it....