When you're monitoring the temperature of a Lenovo, or any computer, what you're really monitoring is the temperature of the CPU cores. The CPU cores are the computer's engines. If they are running too hot, then your entire system may overheat, which can cause the computer to freeze. Lenovo computers do not come with built-in core temperature monitoring software, but there are many free third-party programs that can.
Download and install Speccy. Launch the program after installation is complete. Click on the "CPU" icon on the right side of the program window. Click on the small blue arrow next to the name of your CPU. The temperature of your computer will be displayed next to "Average Temperature." If your Lenovo has multiple cores, the temperature of each core will be listed beneath that.
Download Real Temp. The program does not need to be installed, just unzip the files to a directory of your choice. Double-click on the "RealTemp" application file. Look under "Temperature" to see the temperature of your Lenovo's CPU cores. RealTemp can be used for all Intel single-core processors.
Download and install CoreTemp. Launch the program after installation is complete. Look under "temperature readings" to get the temperature for each of your computer's cores. CoreTemp is free and uses the Digital Thermal Sensor in Intel chips to produce an accurate reading.