[DwightSchrute]

chances are, it probably wasn't that hot anyway. i know for me, i can touch my 2200 after some good hard speed runs geared 43/25 and the thing feels like it could burn my finger off, but when i hit it with my temp gauge, it's most ofthe time 150-165 degrees.
the point everyone is making is, get a temp gauge. they only cost about $20 and everyone who runs electric should own one.

that being said, if you did overheat it, Arct1k said it best. it'll heat up very very quickly and you'll notice a drop off in speed, and if it's damaged much more than that it'll start cogging as well.