What do you do if your computer overheats often?

Check the cooling fans for the computer case or power supply. Also for the CPU chip and the graphics chip (if it has a fan). If they are not working, they should be replaced or taken to a qualified service person to take care of the problem. If there is a filter in front of the fan it should be free of dust and dirt. If necessary clean the filter as well as any dust on the fan blades.

Sometimes people overclock the CPU to make the computer faster. Overclocking makes the CPU faster but also makes the chip run hotter. It may need a better cooling device to drain away the additional heat.