What can really cheese some off is the usual 2 year life cycle of these phones. I see this debuted in March 2013 so it's clearly getting to the point where it's not expected to last much longer.
I checked and see only a 3 to 12 month warranty so if yours did that in warranty, what's the issue?
I can find folk that claim this to be an issue with many models by many makers but nothing points me to where it's more than a percent point of the product and all I found were older (1+ year) phones.
I have heard many times of the S4 overheating and I am one of those who have one that over heats alot. So much so that the battery has started to bulge and is pushing the screen up and off the phone it self. There are so many problems that can cause damage to phones and people that there should be a recall. Like automobiles. Wish I could attach the picture of the screen popping off the phone but this editor won't let me. Trying to use the dropbox link.