You should protect your CPU by providing proper CPU cooler fans especially made for CPU and you should also apply the thermal paste on the CPU casting before fixing the CPU fan and you can also protect the CPU from overheating with the help of BIOS setup.

In the BIOS setup there are two option to prevent from overheating as you can set an alarm when the CPU reaches the maximum level the alarm is being rung and computer automatically shutdown. And if you are going to apply these setting configure them to very low value or the PC will shutdown making a siren noise even it working at it normal temperature.

The CPU as well as all the system fans can be monitored and check that they are spinning at a speed of almost 1500 RPM if they are spinning very less than that you should replace that fan and even with the help of setup you can lower the speed of the fan but it will not provide proper cooling to CPU during playing high end games or movies as CPU during this level generates more heat and it should be released out quickly. And the option of the setup differ from motherboard manufacturer.