[cwbeasley]

Tacking on to what Daniel said, the CPU creates heat, but also the radio polling the tower does too. Spend a complete day in an area that has 4+ bars of signal strength in it and you'll notice your phone generating less heat. If you live in a weak signal area, you'll have more heat. I've spent about 3 weeks doing exactly that, not using the phone, just having my extra phone (a diamond) on and recording the heat. The better the signal = less heat.

Solution: MOVE!!