Sorry to bump an old thread. But I'm definitely getting this.
I'd been using my OPO for Hangouts video chat over H/H+ network, with a fairly strong signal. I noticed afterwards that around the camera area it was just about bearable to touch.
Just recently when using hangouts for video chat, it will get to a certain point and turn off the phone. I presume this is a safety shutdown because of heat. It's happened three or four times over the past week.
Think I'm going to have to take the plunge and either factory reset ... OR try a different ROM. (Currently on Stock).