Why does my device overheat so often?

Why does my device overheat so often?

Good afternoon, I have a big problem. I have Asus Eee PC 1005HA. And it started to overheat very often. I often have to work at the computer and write a lot of articles, but lately my device began to overheat and shut down very often.

How can I solve this problem? Should I upgrade to a more powerful device, or is there anything else I can do about it?