No, not the lunch food .... my 3GS. WOW - This thing can really get HOT ! And I even have a relatively thick (Switcheasy Rebel) case on it. I just purchased SYGIC navigation app and was doing a POI search. While it was searching I put it in my shirt pocket as I always do and I forgot about it. SYGIC keeps the screen on (my choice). All of a sudden my "pocket area" started to feel extremely hot. For a second I had no idea what could be causing the heat on my chest until I looked at the iPhone and it was still (15 minutes later) searching for a POI. No damage to me or (I hope) the phone was done, but it was painful .... right through the thick Switcheasy case. I can't imagine how hot it would have been if the case was off. It remained hot for such a long time I stuck it in the freezer for a minute to cool it down and prevent damage. I have read where the Lithium Polymers batteries (also used largely in radio control planes and helicopters) can becomes extremely hot and even explosive. There are some nasty demos and warnings of this on Youtube for the R/C model hobbiest. I wish I had one of those IR thermometers where you "point and shoot" at an item to read it temperature. This was REALLY hot to the point of discomfort.