If it was powered off, then it should be no problem. Like Andy said, just let it come to near room temp before turning it on.
There is a range of operating temps for computers, but that is for when they are powered on. Extreme cold usually only causes the battery to get weak, so your system my act funny and shut down, or not power on at all (you might see a message about a P.O.S.T. failure - or Power On Self Test). Cold shouldn't hurt it, though.
Now operating in extreme hot conditions is another matter. I work in what would otherwise be considered a walk in refrigerator every night in order to keep all of the systems cool. I think I'm one of the few people in the world who bring a hoodie and fleece to work even on the hottest days of summer.