1. The surge of good feeling that shoots through your body when you have been standing in the cold all day and you go in a heated house or building.
2. The comfortable feeling after exiting the shower, drying yourself off, and going under a big blanket.
After freezing his ass off waiting for a cab, Joe went inside the Coffee shop and had a Warmgasm.
I was camping and had to piss in the middle of the night, I then proceed to enter my sleeping bag and have a Warmgasm.