I have recently been messing around with a raspberry pi at work (a Pi2 model B) for driving display screens for our In-Venue product of which I am the product owner. And very exciting it is too, because the real world is the new frontier (this pdf is also a good primer). If you see what I mean, but more on that another time.
So.. I had to overclock the Pi to improve browser performance to even get near to acceptable speed and smoothness of animations. Pro Tip, the Pi is not a graphics device! Having done this and got acceptable results for a clunky prototype to demo with, and load averages that stayed on the sane side of normal I thought I'd better see if I was frying the CPU. And because I will inevitably forget this useful command I'm saving it here for posterity. Here's how I got the temperature reading..