When a computer operates, the central processing unit (CPU) generates heat; the more the processor is strained, the more heat it will produce. If a CPU gets hot enough, it can cause a computer to crash or shut down unexpectedly.
Computer motherboards are loaded with a basic operating system called a BIOS that will make a computer shut down if the CPU temperature surpasses a certain level; the exact shut down temperature will vary based on the BIOS settings, but generally ranges from 70 to 100 degrees Celsius.
The purpose of setting a shut-down point for CPU heat is to prevent damage to the CPU.
Every CPU should be given a maximum temperature rating by the manufacturer, and the BIOS should be set to shut the computer down if that level is exceeded.
BIOS settings for your CPU can be checked or altered by restarting your computer and pressing the appropriate key to enter BIOS setup (a prompt should appear on the screen telling you what key to press to enter setup).
Computer crashes caused by CPU overheating can usually be prevented by making sure that the CPU heat sink and fan are operating properly, the case is free of dust and by avoiding running too many taxing programs at the same time.