Why won't my iPod power up or get recognized on iTunes?

I put my iPod touch 4th generation on charge one night right before I went to bed. I woke up and went to turn it on but it was very warm and wouldn't power up. Now when I plug it into iTunes it doesn't even get recognized. I've tried resetting and putting it into DFU mode but that didn't help either. When I plug it into a charger the screen stays black.