Isn't this also true for someone with severe respiratory problems?

Hot tub

That's pretty much the case even now. My wife is a Finn--dual citizenship, actually. We spent 2 weeks there last summer. Every house/apartment we went to had an indoor sauna. But, the real treat is the wood fired outdoor sauna. Often built along the lake at one's "cottage" in the country, if one is a city-dweller from the Helsinki area. It's part of the culture, and it's a fun thing to take part in. Outside of couples or immediate families, it's segregated by sexes. "Sauna beer" plays a big part. You have to re-hydrate, after all. The drill goes, get sauna up to at least 80C, throw water on to make löyly, switch yourself with birch leaf branches, then jump in the lake/pool/under the shower, then sit for a spell and have a beer. Repeat as many times as you can stand it (or stand up after too many beers). Then shower, or use a tub of mixed hot/cool water to wash.

One of her cousins is a little nuts, if you ask me. His "cottage" is on a river. In winter, they cut a hole in the ice, line the ice with candles so they can find the hole from below the ice, and jump in the river between trips to the sauna.