Headwear for nights at 0F

Without knowing the rest of your setup, it's difficult to make a suggestion. Do you have a hooded sleeping bag or quilt? Tent? Tarp?

I'm in a single-wall tent with a hooded bag, merino base layer with hood, and down jacket, also with hood. I've been below zero in that setup.

Of course I would forget that.

Hammock with underquilt but no top cover, supplementary CCF pads for foot and head areas, 0F sleeping bag used as a quilt (so hood is in the wrong position to be of any use). My down jacket has no hood.

My coldest night yet was 17/18°F. I was using a Downworks down balaclava and my head was gloriously warm. I didn't even bother to cinch the face closed.

Katabatic make some nice hoods for really cold weather.
They have been reviewed.

Cheers

Roger recommended to me a long time ago to get an insulated baclava and it has made a big difference. Mine is a little light on insulation and I sometimes need to add a Smart Wool baclava to the system. One of my next purchases is going to be a down version.

Usually just the hood of my down jacket. As temps drop below zero though, I like to use a myog buff made out of the sleeve of an old cap 2 shirt. If I feel like my cheeks are getting frosty, I can pull this up over my face and still breathe through it comfortably. I've never enjoyed the smothering feeling of a balaclava over my face, so this works better for me.

I've been out quite a lot to -40F, though my winter mummy bags have hoods. I use an insulated biking skull cap from Nashbar for my head. Unlike most beanies, it is extra long in back and on the sides, so covers the neck and doesn't come off as I roll around at night. When its really cold, I wear it under my OR windproof balaclava during ascents.

Nice thing about a fleece balaclava is you can pull it over your mouth to help warm the air that you inhale and remove at least some of the moisture from the air you exhale so you don't have ice from condensation around your sleeping bag hood's opening. For me, the draft collar on my Western Mountaineering bag means I can snug it up close to my neck and leave the sleeping bag hood looser for more ventilation of that exhaled air.

Admittedly it doesn't get that cold out here on the left coast! At zero or below, I might want to add a second layer, like my beautiful merino wool knit cap from Katharina Pierini!

for 0-ish weather w/ a quilt, I'd highly recommend a down hood (I'd second taking a look at Katabatic), you'll still have a hat w/ you that you can add if need be

you don't want a cold head at 0 :)

you don't want a cold head at 0 :)

INDEED! And a typical prone resting person (at 1 MET) with a cold head will soon be chilled elsewhere even if the rest of the sleep system is adequate for the temps.

Like others have said a good balaclava is essential to keeping warm when using a quilt. I myself have had good luck using a combination of a fleece had with tie-down ear flaps combined with a fleece balaclava.

In my hooded bag, I've used an acrylic balaclava down to 15 F. The acrylic is looser fitting and seems to allow me to breathe through it easier. It was mostly to keep my fully exposed face warm. I plan to make a Climashield balaclava for colder temps.