What type of plane? It could be just for "ventilation" no AC on the plane and it gets hot on the ground quickly.
My google'ing didn't come up with an answer, so obviously I'd ask you guys!
Been watching that show 'Dangerous Flights' and noticed that every time they land they always immediately open the door on the plane. (while taxi'ing on the runway)
This have anything to do with pressurization?
We used to do that in the 402 to keep cool. In fact...
On the Beech we have an ACP and we have a VCM (works like a car's AC .... which is all it is) but we still open our vent windows on the ground to get more outside air flowing the avionics just get very hot in the cockpit.
On the Saab, there are no windows to open and I heard it gets really hot !