I'm having the same heating issue, but I've noticed that I have the famous 'mediaserver battery drain' issue too. Check under "Settings -> More -> Battery" and see if "Mediaserver" is at the top of the list, and if so, what percentage? Mine is sitting at 55%.
I'm down to 31% battery life after 2hrs 43mins of use
I suspect the overheating is a sympton of this misbehaving mediaserver, but I could be wrong
*=- Samsung Galaxy S4 i9500 Exynos Octa-Core 32gb BEAST -=*