Heat is your computer’s enemy. It can damage the internal components, such as the processor, memory and hard drive.
You want to make sure you keep the dust out of the inside of the computer. Keep a can of compressed air handy and use it on a regular basis to banish the dust.
Laptops, need a bit more care. Yes, they are wonderfully portable, but this opens them up to a host of abuses. The fan sits underneath the laptop, and must be kept free for air circulation. Don’t let them sit on blankets, blocking the air flow to the vents. Laptops are best used on a flat surface. You can purchase a laptop desk for use when lounging around on the couch.
Don’t leave your laptop in hot cars, keep them dust free, and use care in handling and opening the case.