this must mean it overheated the first few times and you kept turning it on( because there is rarly a problem with the amount of time you play on the computer and programs., if you are good with computers you can take it apart and check the cpu(ONLY IF YOU ARE GOOD WITH COMPUTERS Do not do this if you do not know what do do inside a computer) The best bet is to call a computer repair company(I do not know if Best Buys GeekSquad can help I doubt it but you never know)
I Might have had a situation like yours but as I was going to upgrade my pc the next day, i did not worry about it.