Cargo compartment heating is completely automatic. There are no controls or indicators in the cockpit.
Each compartment has a cargo heat fan that circulates cargo compartment air to even out the compartment temperatures.
Supplemental heating of the forward cargo compartment is not required. Supplemental heating of the aft cargo compartment is accomplished by an electric heater in the duct downstream of the cargo heat fan.
Supplemental heating and cargo heat fan operation is dependent upon sensed cargo heat temperature.