Just like Sabrina said, it could be the effect of over usage. Not necessarily using it too much at one time, that could be the issue but i think you might just have too much information on your iPad. What happens is we use them for so long, and it keeps track of everything we do, so history, and other un-needed things get piled up. So what you need to go ahead and do is back up everything, save all of your information, pictures, notes, whatever, and remember which applications you are going to want to put back on it then go to setting - Genereal - all the way to the bottom,- back up and reset - erase all content and settings. Make sure it is charged 100% before you do it, and avoid doing it while its hot. So charge it up. Turn it off for a few days like Miss Sabrina suggested then do the reset. You dont want to do the reset while its on charged, especially since its already having a heating up issue. If doing the factory reset does not work, then it must be your battery going bad. If thats the case, you might want to just take it, or send it in to apple. I hope this was helpful!