Very sad to say that I'm an unfortunate owner of a 15" Retina MBP that I took in to the Apple Store to get checked out.
I was unable to recreate the overheating issue in front of them so
they took it in to do some extensive tests and they found nothing wrong.
I showed them screenshots of my fans spinning at almost 6000RPM and temperatures of 215 F.
They said programs like iStat are unreliable.