My camera - frozen?

I was recording a video on my camera earlier, and i set it down whilst it recorded. When i went to press stop so it would stop recording, and to review the video i had made, the screen was black but the little yellow/green light kept on flashing. I pressed the on/off button down for about ten seconds, but the lens were still open but there was no activity from the actual camera menu or anything. It's frozen - but the lens is still open, and i took the batteries out to charge. What do i do?