The silent killer of laptops is heat. The CPU and graphic chips on modern laptops run hot. A copper heat sink and fan attach to these chips, transfer and pump hot air out of a laptop cooling system. Over time dust and lint builds up and block the air vents impeding airflow. This blocks the hot air from escaping. When this happens you will feel the bottom of the laptop get unusually hot and the fan maybe on more frequently.

Cooling System Clean Up