Originally Posted by bealine
(.....and an unheated short-haul aircraft hold can achieve temperatures of -20 C, a Trans-Atlantic aircraft hold will occasionally get down to -40 C).
I do not know where you have those numbers from, but I can assure you that holds, even unheated ones, will not get below 0°C.
Al holds are heated by the way. Some directly, some indirectly by cabin air flowing between the hold and the fuselage.