Hot? Yep!
I have a MacBook Pro circa 2013 that's had a lot of different OSX installed on it.
I think I may have run 10.6.8 on it at one time.
In any event, when I went to 10.12 my computer got really hot.
How hot was it? Hot enough to make me order another laptop before this one hit the big casino. (Apple marketing?)
So hot the video began to have problems AND the machine would go into continuous reboots until it cooled down.
I installed smcFanControl (thanks!) to monitor the temperature and saw the temperature go .... over .... 200 .... degrees F. before my video went psychedelic on me and my laptop began to perform the reboot tango. No, that's not a typo, I did say over 200 degrees Fahrenheit.
I reformatted and reloaded the laptop a few times to see what the hey!
Still smokin' hot!
I erased the drive and re-installed OS 10.9.5, which by the way makes the machine slower to use than 10.8.5(memory management "improvements". Note to marketing. Invest in memory).
And now that 10.9.5 is running? smcFanControl tops out at 120 degrees Fahrenheit.
No more psychedelic auto-cooldown reboots.
What's my problem now? What do I do with that extra laptop?