Overheating PC can cause many system issues like lockups, random restarts or even damage to internal components.
It is a good idea to monitor the temperature levels of key PC components like CPUs, graphics card and hard drives.
HWMonitor is a free lightweight tool for Windows that does just that. Not only it displays the temperature levels of these components but also displays other information like voltages, fan speeds and so on. (The Pro version has other additional features like remote monitoring, graphs and more detailed interface.)
Download and install it from here. Once installed, simply run it. All the necessary information will be displayed.
Just knowing these temperature levels can often resolve many PC issues that are caused by overheating or poor ventilation / air flow.
The entire detailed hardware report can be saved as a text file for logging purposes if needed. This is by File > Save
This is an essential system tool to have at disposal and becomes useful when troubleshooting PC problems.