If dust builds up in your CPU heatsink (and it always will given time) the CPU will eventually overheat and shut down randomly to protect itself from burning up.

The fix is easy. Every six months take the cover off your computer and give it a good dusting with compressed air. Pay close attention to the heatsink, and remove any loose dust bunnies that may have bred inside the case. If you smoke, the insides of your expensive PC are likely covered in a gooey yellow film that is difficult to clean out, and should remind you to quit. (it’s not good for PC electronics either)

This semi-anual check up is also a good time to dust out the fans in the power supply, and check to make sure both CPU and PSU fans spin freely. When fans wear out they seize up and stop rotating… that’s certainly bad for the hot components below either.