Heat in ANY airplane is usually an issue, especially when it is so cold out in the dead of winter. The PC12's that I fly have a hard time keeping up with heating the cockpit/cabin when it is below 20 degrees F or so outside on the ground, and doesn't get any better with altitude. You would THINK with a PT-6 up front, and ITT's running around 700C- 720C, a LITTLE heat would come out!! I've had flights where the cockpit temp dropped from a Balmy 12C down to around 4C inside, and you could see your breath.
The flip side...now that it is summer, you fight to keep it COOL inside
