iPhone 4 Extremely Overheating After Upgrade To IOS 6.1.3 Help!

So I stalled.... And stalled... And stalled some more on installing the 6.1.3 software update until my iPhone 4 started going to crap on 6.1.2. I finally did the update about a week ago, and it has been a nightmare ever since. The battery drainage problem I knew about, but was already experiencing previously.

The massive overheating issue was one I wasn't aware of. I charge my phone and naturally it gets warm then occasionally, but now it gets super hot when plugged in. I don't use my phone for hours at a time sometimes and yet when I pick it up the thing feels like I've been using it all day and can barely be held it's so hot. The screen is starting to look funny developing weird spots in the glass like its almost melting it. Has anyone else had this problem?

I'm eligible for upgrade status, but my question to that would be is the iPhone 5 handling the software any better?