When I was a kid I had one of those little sterno stoves and often used it to cook eggs and heat soup etc.

I found it cooked food well enough for a kid and I am sure a can of the stuff would produce enough heat to warm the inside of a tent or vehicle considerably higher than the outside air. Certainly at least as much as several candles which are quite effective.

Maybe it could be useful to drive off the dampness a bit before sleep, though of course if there is carbon Monoxide potential your sleep may be deeper than you'd like...