People do debate the health benefits but having lived in Finland I certainly got the impression that sauna does help you.
Its importat first to mention that if you have certain consitions then you could do yourself more harm than good ie if you are heavily pregnant or if you have high blood pressure etc.
Otherwise it is great because you sweat all of the rubbish out of your system and also you just genuinly feel mentally so much better. I am convinced it is excellent for your skin and toxins and people underestimate the mental benefits.
For days after you feel so good and if you live in somwhere like England where I do, you need something to make you happy as you walk to work in the rain on a Monday morning.

Besides relaxation one key benefit of the sauna is a marked increase in your body’s production of HGH.
Once a day for 20 minutes following your workouts is enough.
If you experience light headedness or stop sweating, stop immediately.
Making sure you stay hydrated is the important thing.
Enjoy!