About six months ago I got a MacBook Pro with Retina Display and what’s not to love? But like the previous generation MacBook Pro I had, I notice every once in a while that the cooling fans spin all the time. Restarting doesn’t help.
When this first started happening with my last MBP, it seemed like maybe my machine was aging and had lost its ability to dissipate heat without running the fans all the time—kind of like MacBook menopause. But then it started happening on my new machine, too.
At any rate, a little hunting on Apple’s support site revealed it’s a known issue that can be solved by resetting something called the System Management Controller.
(Really, I’m just posting this so it’s easy for me to find this link when I need it, because I always forget how to do it.)