That sounds more to me like you have a problem with your computer's cooling system. If this is the case, it's a simple fix as long as you're not afraid of messing with the inside of your computer.
First, what you would need to remove the cover or casing from your computer to get to the motherboard. If you're using a laptop, you may need to remove the whole motherboard to get the heat sink off of the CPU (or in the case of a laptop, to get the fan off the heat sink first).
Then, you will need to clean the crap (like the layer of dust you will likely find between the fan and the heat sink) off of the heat sink. This can be done with your fingers on the most part, but you may need a can of compressed air to be able to do get all the finer bits in between the slats of the heat sink.
Next, you will need to use rubbing alcohol and paper towel. Place the paper towel over the bottle of rubbing alcohol, then turn it to dab a bit of it onto the paper towel. Then, you will need to rub the paper towel with the alcohol over the top of the processor and bottom of the heat sink to remove any remnant of old and likely dried out or cracked thermal grease from the contact points.
Lastly, before putting it all back together, you will need to apply a high quality thermal grease to the top of the CPU itself. This should be done in as thin of a layer as you possibly can, and it must cover the entire surface area. If your computer's manufacturer used one of the cheap ass thermal pads instead of thermal paste, do yourself a favour and throw that shit away. The thermal pads are pure garbage and only cause more and more problems over time as they get older, especially if your CPU has been overheating. For more information on how to apply the thermal grease properly, please see this YouTube Video: https://www.youtube.com/watch?v=rjF5jabXRCY
If you have questions about how to do this, or would like some assistance with how to do it, please let me know. This is the kind of thing that I do for a living, so I'd be more than happy to give you the information that you need and get you setup with the proper stuff that you need to do it. You will also notice once this is done that your computer will seem to run a lot faster in general.