The problem is that over time dust and other particles clog the vents, fan and exhaust port or radiator of the system thus restricting air flow and cooling. This is fixed relatively easily by blowing out the vents and fan with air or using a brush or earbud (Q-tip) to clean away the dust. Remember: In the computer world - DUST DESTROYS! There is however another hidden problem that occurs when computers (laptops) heat up or overheat. They tend to dry out the thermal compound that conducts the heat thus causing the system to overheat more quickly. Luckily most CPUs, GPUs and chip manufacturers have built in protection for this. They step down the operating speed bit by bit until they eventually switch off the CPU and thus the system shuts down. So if you have a computer system that starts working slower and slower and then switches off for no apparent reason, overheating could be your problem.