Further to Q12) “Is the dog going to FREEZE TO DEATH if they load it by mistake in the REAR cargo hold?”
I found this in Boeing publication D6-76300-32, Detail Specification for a 737-300
Air Conditioning
21-27-00 CARGO AIR DISTRIBUTION
21-27-10 Forward Cargo Compartment
Forward cargo compartment stabilised air temperature shall be maintained above 40 degrees F everywhere at a distance more than 8 inches from the exterior walls and floor in flight up to maximum certified altitude. The cargo door area shall be excluded from this requirement.
21-27-20 Aft Cargo Compartment
Aft cargo compartment temperature shall be maintained above freezing (32 degrees F) when measured at least 8 inches from its exterior walls and floor. The door area shall be excluded from this requirement.