Thanks for all the interesting and informative replies.

It looks like the fur-edged hood is almost universally recommended. I understand closing down the opening of the hood a bit to trap some warmer air, but I am still not sure I understand why it is fur instead of fleece or foam or just the physical shape and structure of the hood, if it's just a wind block. I understand fur as a superior insulating layer, though, but I usually think of that as a layer, rather than a barrier. I'll just trust the judgement of people who have more experience with this stuff.

I'm still trying to find a more portable solution in a hood or face mask for occasional use during severe cold snaps. I assume it is best to avoid openings around the eyes, nose, and mouth that expose patches of vulnerable skin. But the ones that cover the nose and mouth, encouraging moisture and ice accumulation- I picture them making the situation worse.

Instead of a scarf I use a big thick neck sock thing. It's long enough that I can pull it over my ears for an extra layer. Scarves always seem to require a lot of constant fiddling. Is there an advantage to a scarf?

Is there no way to protect from frostbite on the face without either using a hood or constantly dealing with soggy or frozen face masks? What do the Everest guys do, for instance?

Thanks for the interesting discussion?

David