It's a perennial problem with the BA 400's I'm afraid,
Actually it's a general problem with the 744 no matter the operator. As previously pointed out the IFE system is the major contributor. Coupled to that a/c that are generally full of pax. generating their own heat can leave the system really struggling to get the temperature under control. This is especially so at the back of the cabin.
Even in the winter, plugging in external power, turning on the cabin lighting and 'firing' up the IFE can get the cabin to 30 deg C in a very short space of time.
