Atanvaro:
That doesn't begin to say for how long periods that means. Staying in a cold or hot climate is a different thing than just going to a sauna briefly.
I just called my mom's neighbour (and mine for 18 years) Keijo Häkkinen who is a Ph.D. and Vice Head of Department of Biology of Physical Activity in Jyväskylä, Finland and has been counceling both Finnish and international athletes. His special field is muscle tissues (wrote articles for example on: Biomechanics of strength training and Training and neuromuscular adaptation in older age).
He said that a short sauna visit is like having a bit of massage to relax your muscles and make you feel better. Then he (re)told me how their family was over five years ago in USA for about half an year when he was asked to lecture in Pennstate and they made week stay in Chigago when he was counceling the Bulls they stayed in a motel that had a sauna. The family of the professor is him, his wife and three daughters whom the oldest is year younger than I am but she wasn't yet 18 at that time. They got excited that they can go to sauna as they usually go with the whole family once per week back home in Finland. Sadly there was an age limitation to be 18 years old to go to the sauna. They went talking to the owner who said itsn't it a bit kinky to go to sauna with their children (no, not in Finland, it's common like going to a pool or bubble bath with family or friends) and that he doesn't know the health risks, what could that do to small child's heart and stuff, and the family promised to take whole responsibility. They go to the sauna and start throwing water to the stones and had fun, but afterwards they got a note that "if you want to go to sauna again, tell us and we will arrange a private hour for you". Apparently other hotel visitors couldn't take the heat..
