You could get an extra shower curtain and hang it at the ceiling to help keep the steam inside the shower. Maybe stick a space heater in your bathroom if you want it warmer. I’d turn on the vent fan afterwards to help get the moisture out to decrease risk of mold.
Take a nice hot shower for as long as you like and let the steam build up. Very relaxing, no additional equipment needed.
Isn’t the same as a sauna tho…
You could get an extra shower curtain and hang it at the ceiling to help keep the steam inside the shower. Maybe stick a space heater in your bathroom if you want it warmer. I’d turn on the vent fan afterwards to help get the moisture out to decrease risk of mold.