All of ours are in cabinets and not safes, so I'm ignorant as to the typical method of construction of the safes.
But, seems that with an airtight seal at the door- and some Damp-Rid inside to remove whatever moisture is present in the air inside the safe when the door is sealed, it would be impossible for the humidity level to rise to a point where condensation could take place regardless of outside temperature.
But, seems that with an airtight seal at the door- and some Damp-Rid inside to remove whatever moisture is present in the air inside the safe when the door is sealed, it would be impossible for the humidity level to rise to a point where condensation could take place regardless of outside temperature.