baldeagle lives in arizona, farting in the cab would probably defrost the windshield
i drove my original 58 truck in -10*f with the defrost on full and had a 3'' circle to look out of on each side.
in my panel i had a propane heater placed on the floor in between my legs, pointed at my feet.
and yes, the vintage air heater will run you out of the cab on my truk
it will also frost your toes in 105*f heat