Just to add to this discussion, I have an i5-4690/m295x that was bought this past June. I just started gaming on it a few weeks ago (mostly some Far Cry 4 on Windows 7, sprinkled with a little Civ 5 on OS X), and had to take it in to the Apple Store a week and a half ago because the GPU burned itself out. I was assured by the technician at the store that this was just a faulty part, but judging by this thread, I might just be the first of many failures.
They replaced the logic board, assured me everything was good, and sent me on my way, but I'm now actively monitoring the machine's temperatures. I've been getting the same results everyone else has been seeing, ~105°C GPU temps within seconds of starting a game up. I'm going to continue gaming on it (I'll be damned if I spent that much money on a machine and can't get at least some gaming time out of it), and I'll let you all know if I manage to burn out a second card...