Also worth noting, vehicles seem to have internal temperature even if they have no sort of power - as long as the tile is "indoors" on the vehicle then it gets some temperature control. You might be able to put together small 3x3 bunker-boxes of boards, doors, and roofs, allowing you to slip inside to warm up and make excursions into the terrifying cold.
You are one of our top experts at spotting exploits, thanks ^_^'
This will be addressed when vehicle-borne electricity management is working, which is crawling forward.
Sorted out some issues with battery stacking, soon vehicles will be populated with lead-acid batteries, then the fun can begin.
Addendum, something that SHOULD work and isn't exploit-y is dropping a big pile of blankets or similar on the ground and sleeping on them, you automatically burrow into the pile and get a warmth bonus as if you were wearing them. Might look at doing this while waiting as well so you can do a bundle up type thing when you don't want to/can't sleep.
FYI, to count as inside, you need 5 frames and roofs, arranged in a '+', the center of which will count as "inside". The perephial squares can be boards, doors, or any other impassable obstacle instead.
For climate control we really nead something like "sealed" in addition to "inside". Inside really just implies "under a roof", but we're also using it to imply "sealed" right now, hence funny bugs like a golf-cart like thing with no sidewalls at all protecting you from smoke. (I think...)
Found something that should be a bug: When crafting a molotov, the bottle holding the whiskey doesn't count. You need an empty glass bottle AND another bottle containing whiskey!
This is an issue with the crafting system, it basically doesn't handle containers properly. It seems there was a TERRIBLE and hacky override specifically for molotovs at some point in the distant past, but as is common with hacky solutions, it bitrotted and doesn't work anymore.