I had my ipod on a dock its been on for a y...

I had my ipod on a dock its been on for a year now and when i woke up in the morning it was really hot and didn't charge. Ever since then when i put my ipod nano on either the usb port on my computer or my i-home and my dock, starting at the base of the ipod gets really hot. When this happens and i take it off it never holds it's charge, even if i try to leave it on for a while. The only place it charges is in my truck where i put it in my power out-let to play it throw my radio. Is it dead or is something wrong.