Anyone start to overheat or not feel at random times compared to others.

Like I’ll be in the shower and won’t have the water too hot but will gradually start getting too hot and not feeling well. At the same time I could be in the sauna or laying outside and not overheat like that. Anyone else experience that. Anyone have any advice or insight to why this happens.

Before anyone says anything I know saunas are not safe but the one I use isn’t at that hot of a temperature and I don’t stay more then 15 minutes.