In most cases, you are not supposed to be worried about the temperature of your computer. Barring manufacturing defects, hardware is designed so that its temperature does not exceed maximum operating temperature. But even without any hardware fault, overheating can occur due to various software issues, e.g., buggy graphics card driver, misconfigured fan control program, malfunctioning CPU frequency scaling daemon, etc.
Overheating may become serious enough to cause permanent damage on your hardware. So watch out for any overheating issue in your system. Even better, have temperature monitoring system in place, so that you will be alerted if system temperature suddenly goes up.
In this tutorial, I will describe how to monitor system temperature on Linux.
There are several user space tools on Linux, which allow you to check and monitor temperature of various system components.