Sauna is a powerful detoxification tool

Saunas may also be the single most powerful tool we have for detoxification from environmental chemicals and heavy metals. Sauna use shows real promise for detoxification from heavy metals, synthetic chemicals, drugs, and pesticides.
Many toxicants have long half-lives and bioaccumulate up the food chain, so even if you are avoiding new exposures to the extent possible by cleaning up your immediate environment and being careful about household and personal care products, no one can avoid all exposures and most people likely already have significant stores of toxicants. In our current world, even newborn babies have already been exposed, as a total of 287 toxic chemicals were identified in umbilical cords in a recent study.
In short, even if you’re a health-conscious person who goes out of your way to avoid environmental toxicants, it’s still a safe bet that your body has accumulated some significant burden of nasty chemicals and heavy metals. (And if you haven’t been a health-conscious person who is aware of how to avoid such chemicals, then it’s a safe bet that you have a fairly high body load of accumulated toxicants.) Thus ongoing detoxification is very important.