Sure technically you could slip your own ski hat over your laptop to make a sleeve or put your laptop sleeve atop your head but this multifunctional accessory from Dinglab is actually designed for both purposes. It can also be unfolded out into the form of a scarf. Of course this puts you into the position that no geek ever wants to be in: having to choose between themselves and their laptop! It’s the Sophie’s Choice of geekhood.
The Multimodular Laptop Sock is designed to stretch to fit any laptop from 12″ to 17″. I would assume it can also stretch to fit various head sizes too. $48 seems like a lot for a hat and a laptop sleeve but I guess once you start combining things you can add on a few bucks for the convenience.