Overheating or Power Supply?

This past week Its been getting quite hot in my room due to the approaching summer. Since the heat rise my PC has been turning off at random intervels, particulary when I am playing a game that uses alot of rescources.

However the heat has subsided and I have a heavy duty fan blowing near my PC with the side panel taken off. At random intervels I am still getting non-provoked shutdowns. I was actually away from the PC watching television, and out of nowhere the PC shutdown while idle. I opened it up and felt the HDD, Power supply, and processor for heat. Yet they were all barely luke-warm.

My question is, Could it be time for a new power supply? I am dismissing CPU or HDD being the culprit due to when I boot up im not getting any error messages or alerts of overheating.


Probably unrelated but, can too much thermal silver compound put on the copper of the processor be a bad thing?

Ok, so I manage to get into BIOS, and very fast I go to check on how hot the CPU is. Its running at 114 Celsius, I wasnt able to write it down in time but I believe thats around 230-240 farenheit. Is going from off status at a cold temperature to 114 in a matter of seconds normal?