The manufacturer of your computer or laptop is probably running a program that monitors the processor to make sure it doesn’t overheat.
The CPU could be overheating because it has either too much voltage for its design, inadequate chassis ventilation, or insufficient thermal compound between the CPU and heatsink. Symptoms are hard to determine without inside knowledge of your particular machine. Your best option might be finding someone who can open up your hardware and take a look at what materials are laid down on the components.