Declock the Computer. Change the Front Sided Bus Speed and or the CPU clock multiplier in the BIOS.

Not only will your PC actually boot properly in high temperatures you will save money on your electricity bill.

If your computer is generating heat i.e. 150W to be reduced to 70W then have your aircon remove that heat will save some cash.

You probably wouldn't notice any speed difference with your PC unless using heavy power hungry applications such as video editing.