poor reception and hot to touch

I've a new iPhone 4 - my first iPhone. I'm finding that reception is bad and getting worse. Signal strength varies widely, and I'm getting dropped calls - more than half of all calls. I also notice that the phone gets hot when I'm calling on these dropped calls. These are very short (just enough for the caller to realize than he cannot hear me) calls.

Is this a common issue, or should I be taking this back to Apple for service?

I know that threads of poor reception are common. I have not seen one where the temperature and dropped calls are connected.

I'm fishing for info so whan I talk to the Apple folks I can understand what they tell me.

Thanks!