I am logging this for the record. new white iPhone 4s, started to demonstrate fast battery drain (eg down 30% from a full charge within 2 hrs with little use) and heating up (very warm to touch). Turning off bluetooth, GPS, even wireless helped somewhat but did not completely eliminate symptoms. Then yesterday (take a deep breath!) noticed crescent-shaped crack in rear glass running along 2/3 of phone length. I presented all this at the apple store last night. Their initial diagnosis system saw nothing other than a number of running applications. It was pretty evident from the look of the phone that it had not been dropped or damaged in any way, so they agreed to replace the unit in its entirety. They did look up their knowledgebase to see if there were any reports of overheating (which I suspected might have led to the crack), but I didn't get a sense of the outcome there. Since they replaced the unit, I am a happy camper and the new unit is holding its battery charge much better. The Apple store folk were helpful and I am grateful to them, yet it feels as though I was also somewhat lucky and I had the sense that I could have just as easily been left with a $29 replacement cost for the glass on the same troubled unit.