There’s a saying in Finland that foreign "saunas" are not true saunas at all, but rather just "untypically warm rooms".
The experiments where at 73°C which is a lot hotter than most gym/hotel/spa saunas I’ve been in outside Finland
Also while 73°C is a proper sauna, there are plenty of hotter ones. 90°C is closer to what I'm used to at my apartment building's common sauna. I do take two breaks when I'm there for 30 mims though.
73° hot?
Here in mainland Europe, a "classic fin sauna" is usually at least 90°++
Anything beyond 90 C is not a sauna :) Better to have 90+ and hot steam as in Russian sauna (banya) :)
you can sous vide beef and pork at a lower temperature than that
As an Estonian, anything below 80°C is considered a "kids sauna". 80°C - 90°C is a cold-but-workable sauna and proper sauna starts from 90+°C. I'd assume it's the same in Finland as we share a lot of the sauna culture.