BMW auto colling during high heat when off?

Heres one for you guys. I've had two BMW owners tell me this now. They said that when the car sits in the heat with the car off, no keys in the car at all, that the car will turn on to "cool or vent" itself. Ever heard of this? I've owned 3 BMW's now and I haven't noticed that. But heres the thing; we all live in Arizona where the temps can reach 120 degrees. They said if you go out there during the scorching heat you'll hear the car fans running. Kinda strange but can anyone verify this. If so whats the temp it reaches before it turns on? When does it turn off? Does this kill your battery? I'm trying to still learn everything that these cars do but thats one I haven't read yet even in these forums. Give me some input on this if anyone knows. Thanks....Mike

Well, there are some BMWs that have the ability to be set(using the OBC) to turn on the HVAC fan at certain temperatures (my 1988 750 for example) however I do not believe yours is one. Tehn of course many of the auxilary engine fans will run (right after shutdown) for a few minutes, if the engine temp is high.