You can press CTRL+SHIFT+ESC and a new window will appear. Here, you can look at the CPU usage. Alternatively, you can download "Speccy" from
www.piriform.com. This software will give you extra information on temperatures from the various sensors in the laptop. You shouldn't be scared about using the computer. There is a physical safety within all CPU's now-a-days. After reaching ~100-105 degrees celcius, the computer will automatically shut off to avoid burning components from high temperatures. When this happens, leave alone for 10 mins and you can restart. If no auto-shutoff happening, then you have no overheating. BTW, also check temps and usage on the GPU.