Macbook often goes to max CPU and then hangs there

My MBP 2015 15" often hangs with the same sequence of events. First the fan starts rushing up to top speed, then the screen gets some lag, then becomes unresponsive, and then the whole thing hangs in this max CPU state indefinitely until powered off (you can't even move the mouse). I'd really like to be able to log what software is running so I can start to troubleshoot. I don't have to be using any app in particular to make it hang, and I can otherwise do CPU intensive work like video editing without problems. Any ideas?

I had the exact same issue on my MBP 2017 15", using it with external screens and Mojave 10.14.6. Turned out to be a bug with NightShift (documented here). Turning off NightShift solved the problem.

Maybe this will also help you.