I had a 24x40 slab poured for a walk out basement on an existing house. An enclosed space but not heated. Vapor barrier, rigid insulation, mesh and pex tubing for an eventual boiler. Done during a 20 degree cold snap in NE. They said they'd still pour, just a hotter mix. They told me that it would feel warm to the touch but I could walk on it the next morning. From an adjoining space I watched them work and left the door open overnight. It opened to a 1st floor landing which opened into the 2nd floor main living area. When I got up in the morning the house felt like a sauna. I just had electric bb heat at the time. All my windows were soaked from condensation, as were the exterior walls.
Still 20 degrees outside, I opened most of my casement windows to vent the house. Went out to my shed to get a fan and portable heater and my neighbor came running out of his house yelling that my house was on fire. Looking up at the house I had steam pouring out of the windows. So thick it looked like smoke.
The basement walls were insulated but not covered. Concerned about mold forming, I had to pull down all the insulation to dry the walls and ceiling. Ran heaters and fans for about a week to be sure everything was dry.
I was surprised at how much of that water evaporates out. Next time I'll just wait for warmer weather.