Frequent overheating will damage the motherboard! Here is an extended article on heat and laptops.
The laptop starts beeping, freezes, reboots by itself or turns off after a while, usually 10-15 minutes or more. If you run it again, it will repeat the same thing after a few minutes.
Finding a problem:
Most laptops overheat because the fan receiver is blocked from placing the laptop on a soft surface or dust. In any case, you need to let it cool down before turning it on again (this can take up to 30 minutes).
If you suspect dust is blocking the fan/heatsink, grab a can of compressed air and try to clean it out now (this will also cool down the laptop).
Sometimes overheating is caused by a malfunctioning fan. If the fan is completely stuck, the laptop will display an error message immediately after startup. However, in rare cases, the fan fins are simply loose or broken and won’t move enough air to cool the laptop.
In any case, you should try cleaning the fan and heatsink with compressed air. This is best done outside, as a surprising amount of dust usually accumulates there. If the laptop continues to overheat, you need to take it to a repair shop.
Also, if you dropped your laptop, the screws holding the heatsink might be damaged. In this case, the laptop will overheat in just a couple of minutes, as the processor has lost contact with the heatsink and is not cooled at all.