Hoods - a better way to use them?
You can lose up to 80% of your body warmth through your head. Come what may, frost bite and the rest, your body will keep your head (and the grey matter inside it) warm. If that means stopping the blood flow to your feet so they get frostbite, so be it. Y
You can lose up to 80% of your body warmth through your head. Come what may, frost bite and the rest, your body will keep your head (and the grey matter inside it) warm. If that means stopping the blood flow to your feet so they get frostbite, so be it. You can be standing out there in a gale, shivering away, and your bare head will still feel warm. What this means in practice is that you can be lying there in your bag feeling horribly cold in the lower half of your body while your head feels quite warm enough. I know how some sleeping bag manufacturers claim they have added extra insulation to the foot box to help keep your feet warm, but that is total marketing hogwash. The problem does not lie at your feet: it lies at your head. The solution is to keep your head warm! That's is what the hood is for.
The conventional way of using the hood is to pull it around your head and tighten the front draw cord. After all, all you really need is a little air hole in front of your nose. Claustrophobia? Maybe so, but being warm all over is much nicer! One thing we can guarantee is that even if you rotate right around inside your sleeping bag, you will NOT suffocate: the material in modern sleeping bags is too thin to allow that to happen (with the obvious exception of bags using DriLoft and similar). Just shut your eyes and you won't notice. If this is how you want to use the hood, then when you buy the bag make sure the hood comes around your face nicely, and that the drawcord is easy to adjust. A shaped hood helps. You should be able to reduce the opening to almost fist size. A good mummy or tapered sleeping bag should also have a neck muff: this goes around your neck to stop cold drafts from going down inside your bag. The muff may also have a draw cord to help block drafts.
A Better Way
However, you don't have to use the hood that way. After all, that leaves a major part of the hood insulation wasted, squashed flat under your head. If you don't have a pillow, the grease from your head is grinding into the hood fabric and the down. Yes, there is another way of using a hood, even in the snow - think doona! Put the sleeping bag upside down on your mat before you get in *. Put your pillow under the hood. Get in, and pull the hood over the top of your head, just like you might pull a doona over your head at home. Your mat and your pillow will keep the underside of your head warm; the hood will flop down over your head and keep it warm too. You might like to have a small fleece ski-cap as well: it stops drafts. Note: you do not have to do up the hood this way, nor do you have to have the bag tight around your neck! You can thrash around under the hood with no problems. You can tuck the hood back a little if you are getting too hot, and you can pull it right over your head if you just don't want to know about the outside world. This happens sometimes! And a lot of your hot breath will stay inside the bag with you, and that really adds to the warmth of your bag.
* This assumes you have a bag which has a uniform thickness of down on the top and bottom. If the quilting goes right around the bag in the conventional manner this should be so. However, some bags have different sorts of quilting, and some even have different amounts of down on top and bottom, or even no down on the bottom. I'll assume you can check this.
""But how will I breathe?"" I suggest you do it in the usual manner, through your mouth or nose. But seriously, you simply do not need that much air that you have to have a direct passage to the storm outside. You will quickly find that the loose lay of the hood on your mat will let in enough air for a very satisfactory night's sleep - just the same as at home under a doona. Just make sure there is a little tunnel to the outside world - you need to see when the morning has come after all. And not having the hood done up tightly is so much more comfortable too. Does this work in the snow? Too right, and very nicely too: I have been doing it for years.
A side benefit of the approach is that you may find you need a lighter bag for the conditions. Conventional bags have 700-800 g of down in them; we have used bags with only 150 of down as low as freezing point. Yes, my wife and I snuggled up together, and yes, my wife had her thermal top and pants on, while I had a thermal top. We have used bags with 300 g of 800 loft down slightly below freezing point quite happily - with our thermals on.