Also not mentioned:
Sauna use linked to longer life, fewer fatal heart problems - Harvard Health Blog - Harvard Health Publications
"Over the course of the study, 49% of men who went to a sauna once a week died, compared with 38% of those who went two to three times a week and just 31% of those who went four to seven times a week. Frequent visits to a sauna were also associated with lower death rates from cardiovascular disease and stroke."
Did the participants that used the sauna 4-7 times a week coincidentally exercise more?