"Finnish saunas, which are typically heated to between 70°C and 110°C (158°F to 230°F) and have low humidity, are the most well-studied. Regular use has been linked with many physical benefits – a lower risk of hypertension, muscular problems and respiratory conditions, for instance. But now researchers are starting to unveil cognitive benefits, too. These improvements include fewer headaches, increased mental well-being, better sleep and a lower risk of dementia."
https://archive.is/t0tUH