I believe that steam rooms are incompatible with human life in the sense that you will overheat and eventually in a hot steam room. Most people are sensible and exit before this happens.

And, like, the entire American south

In fairness it was air conditioning that turned Florida into useless swamp to tourist paradise/trap.

I really hate it because I know it will only make things worse long term but my North European country is rapidly installing AC everywhere now thanks to increasing heatwaves.

A great positive feedback loop, no? Anthropogenic Climate Change (ACC) creates a need for more AC which in turn creates more ACC which furthers the need for more AC. Yeah I don't see this going well for the next few decades.

I've been in steam rooms. You're strongly advised to stay no longer than twenty minutes inside.