[Bells]

Yeah, the most likely problem is that it is overheating. This happened to both my laptop and computer... computer however because bits of fluff from the carpet got stuck inside, so the computer couldn't stay on for too long and kept shutting down! With your laptop, where do you use it? Sometimes it's a safer option to use it on a desk or something, because I used to use mine on a bed which meant it overheated more. So your best bet would be to have it serviced, which doesn't take too long and it's better to sort it out now.