I have an overheating problem with my PC.

Im pretty sure whats happening is the motherboard is overheating and shutting off. After the PC TURNS off the motherboard is extremely hot to TOUCH. It usually only overheats when i run a hardware INTENSE program (computer game). I have tried cleaning the motherboard, mother board FAN, power supply fan, and every other part inside the PC. I even have an external fan blowing on the open PC case, but still the same problem, the PC shuts down about 2 minutes into a intense program.

I was just wondering if I should take my PC to the shop, and if so what is likely the problem and how much will it cost to repair/fix?

Is there anything I should try myself before I take it for repair?

Thanks for your time - OwenFor one, the inside of the computer is supposed to be over 100 degrees. It's supposed to be a bit warm. Two, when you touch the inside of your computer, you always ground the static electricty from your hands, right? Assuming that the motherboard is the issue here, it will cost a fair chunk of change to fix.

FlameQuote

I even have an external fan blowing on the open PC case, but still the same problem, the PC shuts down about 2 minutes into a intense program.