CPU Temp is one thing. Calculating the CW is how it should be measured.
C/W depends on your case temps, cpu core temps, and processor wattage. To be getting a case temp of 45 and a CPU Die temperature of 50 degrees it doesn't get any better than that. But to be having a case temp of say 10 degrees and your CPU die is 40 degrees that's very bad. You see where I am going?