Insufficient cooling is the cause of laptop overheating. The engineering of a laptop is different from the one of a PC and the air flows inside a laptop could cause trouble more quickly. If the user demands more from the device, that can cause the temperature to go up; for instance, having more programs running (pushing RAM and processing), or having the power settings defined to maximum use. Even the brightness of the screen can contribute to a hotter laptop.
Working with a laptop on the lap could have some other consequences. According to a La Times article of 2010, the State University of New York found that the laptop heat could have an impact on male fertility.
Mind that just because a laptop gets warm, it doesn’t mean its overheating. Signs of overheating are related, for example, to strong and permanent fan stress (the fan always working at high speed).
Check out what you could do to prevent this problem.
The most immediate measure is to use the laptop properly, on a flat surface. Forget pillows, blankets, or your lap. Laptops were made to work on tables; you could use some laptop tray to do the trick.
Software intervention is always helpful. You may find out you have unnecessary programs running, that you could live with less brightness, or you could even slow down the CPU clock. If you’re ok with this, it will not only “refresh” the computer but it will preserve the entirety of the hardware.
If the problem still didn’t go away, fix the internal cooling of the laptop – which is something you should do regularly, anyway. This means to disassemble the laptop, clean the fan with a drop of alcohol, and remove all dust from exhaust ports and the intake channels (from which air gets out and in). A vacuum cleaner will be useful, as well as canned air. One should be very careful while disassembling the laptop, removing the power adaptor and battery and avoid any static.
If your computer continues to be too warm, a cooling pad could be a solution. But beware about the kind of cooler your laptop needs. Some coolers suck away the air from above them; if your computer has intake grills at the bottom, it will pull air from underneath, which means a cooling pad removing the air from above will be competing with it – and contributing to its overheating even more. Some coolers merely absorb hot air. Check this carefully before spending money on a cooler.