My computer gets really hot
Most computers get warm after a while, and some can get quite hot. This is normal: it is simply part of the way that the computer cools itself. However, if your computer gets very warm it could be a sign that it is overheating, which can potentially cause damage.
Most laptops get reasonably warm once you have been using them for a while. It is generally nothing to worry about — computers produce a lot of heat and laptops are very compact, so they need to remove their heat rapidly and their outer casing warms up as a result. Some laptops do get too hot, however, and may be uncomfortable to use. This is normally the result of a poorly-designed cooling system. You can sometimes get additional cooling accessories which fit to the bottom of the laptop and provide more efficient cooling.
If you have a desktop computer which feels hot to the touch, it may have insufficient cooling. If this concerns you, you can buy extra cooling fans or check that the cooling fans and vents are free from dust and other blockages. You might want to consider putting the computer in a better-ventilated area too — if kept in confined spaces (for example, in a cupboard), the cooling system in the computer may not be able to remove heat and circulate cool air fast enough.
Some people are concerned about the health risks of using hot laptops. There are suggestions that prolonged use of a hot laptop on your lap might possibly reduce fertility, and there are reports of minor burns being suffered too (in extreme cases). If you are concerned about these potential problems, you may wish to consult a medical practitioner for advice. Of course, you can simply choose not to rest the laptop on your lap.
Most modern computers will shut themselves down if they get too hot, to prevent themselves from becoming damaged. If your computer keeps shutting down, this might be the reason. If your computer is overheating, you will probably need to get it repaired.