Brown Sauna 

To release gas from the anus, so that the air becomes very warm, and moist (like a sauna), but brown from the source.

I ate so much taco bell today, my room is a brown sauna.

Brown Sauna by Rensta April 29, 2008

Brown Sauna 

Wearing dirty undies in a car when the driver turns on the heated seats - releasing the sewer-like armoatherapy into the cabin.

i was in the car after two days at a festival and my friend turns on the heated seats - i knew within 2 minutes it'd be a brown sauna...

Brown Sauna by ^^!$#@ October 11, 2019