Yeah, even the most poorly insulated attached garage is not going to be particularly horrible. Mine isn't great and has never got below 37, even when it's been

Yeah, even the most poorly insulated attached garage is not going to be particularly horrible. Mine isn't great and has never got below 37, even when it's been single digits outside. Fire departments use a system called Plymovent - magnetic rings around the engine exhaust, hooked to a big hose and fan to exhaust emissions outside of the apparatus bay, so rig checks, testing, maintenance can be conducted indoors with engines running. The hoses are also on runner rails so that they can move with the engine, and magnetically disconnect when the engine is on its way out of the bay.