A CPU can only be as cool as the ambient temperature surrounding it. Hot air around the CPU means that your notebook’s CPU is not as cool as it could be. The result is a CPU operating at a temperature higher than it could be which can, if high enough, shorten the life of a CPU.
Although the CPU is likely the number one heat-generating component in your laptop, other components can generate quite a bit of heat too. In particular, your notebook’s hard drive is probably the number two heat-generating component. A hot hard drive increases the ambient temperature in your laptop and reduces the amount of cooling that the CPU’s heatsink and fan can accomplish.
However, hard drives aren’t the only contributors to rising ambient temperature within your laptop. Spinning optical drives such as DVD-ROMS and Blu-Ray drives can add quite a bit of heat to the inside of a laptop. Even external devices such as USB drives can increase the temperature inside your notebook by a few degrees.
To keep your laptop CPU cool, unplug any devices you will not be using for a while and remove any optical media such as CDs, DVDs, and others from their drives to prevent them from spinning up and increasing the heat inside your notebook.
Although you cannot remove your laptop’s internal hard drive, you can tell the operating system to power the hard disk down when it has not been accessed for a specified amount of time. This is especially good advice if you leave your notebook plugged in but unattended for a long time. There is no reason to leave your laptop’s hard drive spinning and adding heat inside of the computer if you are not using it. Also, should you bump into the table on your way back to the laptop, a stationary disc is far less likely to have issues from shock or drop than a spinning one.