Lenovo laptops, and laptops in general, are prone to overheating due to their cramped construction. When running many programs on the laptop, the CPU becomes very hot, which can cause the laptop to shut down. Some newer Lenovo laptops have adjustable fan control, which means the CPU fan speeds vary directly with the CPU temperatures. However, if you want to keep your fan speed at 100% all of the time, you can do so by changing settings in the BIOS.
Download the latest BIOS update for your laptop and install it (see link under References below). Turn off your computer.
Turn on your Lenovo laptop. Right when the boot screen shows up (the screen that lists the parts in your laptop and is in black-and-white letters), hold the "Delete" key to be brought to the BIOS settings.
Select "System Monitor" on the BIOS main menu. Now access "Fan Control" and then choose "CPU Fan Speed Control."
If the control is on "automatic," change it to "manual." Type in the percentage at which you would like the CPU fan to operate (100 would be 100%).
Click "F10" on the upper-right corner of the keyboard and restart your laptop. After the laptop restarts, the CPU fan will be noticeably louder.
Buy a cooling pad to further reduce temperatures in your laptop.
Some Lenovo laptops, such as the netbooks (10-inch screens), have locked motherboards and thus do not allow you to change the CPU fan speed.