The problem of overheating laptops has been around for years. The reason is rather simple. Laptop manufacturers have been trying to make their product smaller and smaller. In order to achieve their goal, they must make the parts, such as the motherboard, hard drive etc. smaller and smaller. They also have to place all these parts closer to each other. The microprocessor, motherboard and hard drive all produce heat. The closer they are to each other, the more concentrated the heat is. The fans that are built into the laptops to cool these components down cannot work efficiently in such tight quarters. Add to this the fact that it's difficult for the heat to escape, and you have overheating laptops. When a computer overheats it's likely to fail [source: Martin]. Here are some tips you should know that will help you prevent your apple laptop from overheating.
Don't put your laptop on anything like a cushion when it is switched on. The soft material could obstruct the airflow vents, especially the rear vents, which could cause the computer to overheat.
Never put anything over your keyboard when the laptop is operating in the closed-lid mode. It's likely that this will cause the computer to repeatedly turn on and off. This could produce considerable heat and could also drain your battery.
Shut down your computer overnight to let it cool off. If you use it intermittently during the day, set it to go into standby mode when not in use. This will save power and reduce heat output from the laptop's components.
Make sure your laptop is always switched off when it's in a bag.
Clean the air vents. Dust accumulates on the vents, which will block them and prevent them from working efficiently. You can even purchase a small electric cleaner to clean dust off the vents.