Phone is fairly new to me, I got it November or so. It's always worked just fine. Today I had it plugged in, walked into the other room for a few minutes and came back. Phone showed an error something like "Charging paused. system is too hot." So my Boyfriend told me to restart it and put in my extra battery (because I have two batteries for it). Did that, powered back up, was working on where in settings I could find the battery temperature and (less than 5 minutes)it told me something to the effect of "System overheating. all apps have been closed, phone can only be used for contacts". So I powered off, pulled out the battery, and now I'm nervous to try and turn it on again. Any suggestions?
EDIT: I'm not rooted