And also replicated with participants not used to high temperatures inside a typical Finnish sauna. As the study said such people are very difficult to find in Finland. But I wonder if a person who has never been to a real sauna would tolerate this study protocol (2*15 min at 73° Celsius) without any training.

Sauna and hot climates may sound counterintuitive, but it has been tested by most Finns that when you come out of a hot sauna any outside temperature feels cool.

Northern Spaniard there, bring a Saunaa lover Finn with one of these climate-change induced hours at 43C at some day or two in Summer... in the Atlantic, in Bilbao, which is... inside a valley. I've been in saunas at 60-70C and the feeling inside was much bearable because of the lack of humidity...

I'm an immigrant in Scandinavia, originally from a hot country, in my experience a 73C steam sauna is quite tolerable for a 2*15 min session.

The first time I was in a sauna after moving was a bit harder than after getting used to it but doable.

Nowadays I just love them, my friends and I built a couple of saunas to leave by the lake in their summerhouses, the cravings of going from hot -> very cold, and back to the heat is hard to explain, and I totally recommend it.