I mostly fly from cooler places. For example this morning, I had a 5:30am departure from CYCG Kootenay in the mountains of British Columbia. OAT indicated on the thermometer was 50, there were scattered clouds and the sun wasn't yet peeking over the mountains. Upon entering the plane, cabin temp was 71F. Within 5 minutes, while setting up, the cabin temp was 98F. Opening the doors cooled the cabin down to 72F in about 2 minutes. However, when I closed the doors (and opened the window), the cabin temp rose back to 78F in a couple minutes - basically by the time I was ready to taxi.

I only bring it up because it's pretty consistent. Enter the plane, start setting up, and before too long the Cabin Temp High light is on. I could understand this rapid rise in cabin temp if the OAT was high, but rocketing up to 98 (one day when OAT was also about 50, cabin temp went to 112!) just seems too fast.

Is anybody else seeing this?