Originally Posted by el_kirk
On really cold days I bring the tanks inside the night before, then put them in a water bath (50-60 F) partway through the boil.
Don't do that again. If you have even the slightest leak you have created a very dangerous situation. Propane is heavier than air so it pools near the floor. Propane also has a much wider range of mixture with air that is flammable than gasoline so if you have any propane that leaked and something creates a spark or you have an open flame, when the propane gets to the mixture that makes it possible, BOOM! There goes you garage or your house and all your family.
It's fine to put the tanks in the water bath to warm them but do it outside. Never bring your tank indoors.