Choosing the Right Sleeping Bag
You remember the days when you grabbed your sleeping bag and built a fort in the living room or stayed over at a friend’s house. The bag unrolled on the floor and the indoor adventure began, but at the time, you probably never thought of your sleeping bag as a valuable piece of survival gear.
A sleeping bag is not just a blanket to roll up in, it is a shelter from the elements and it can save your life in extreme cold weather if you have the right bag. Not all bags are created equal however, and you must match the bag with your outdoor adventure.
Anyone that has camped in sub zero temperatures would probably agree that a mummy type sleeping bag is better designed to keep you warm. However, some may find it a bit constricting so the open faced one or one that unzips into a large blanket, if you will, may be more desirable in milder climates. In extreme cold areas, you want as much of your body covered as possible however, and this includes the head and the sides of your face so make sure your mummy type bag has a hood that encloses your head and face and the hood should be adjustable.
For extreme cold weather adventures, you would want the bag to be able to protect you at zero degrees or lower. Bags are rated at various temperatures but it is better to have below zero protection even if you do not necessarily need it each night.
There is no standard in the Untied States for sleeping bag ratings such as is the case in Europe where they have the EN 13537 standard. What this essentially means is a bag rated for 20ᵒF from one manufacturer in the United States can differ from another manufacture making the same rating claim because there are no standards.
Make sure the bag is big enough for your body. Mummy bags should have extra material at the feet for warmth and enough room so your feet are not squeezed together. Check the shoulder space to make sure you can move around or even roll over inside the bag if needed.
Type of Fill
Goose down in and of itself is by far the better insulator but once placed in a sleeping bag it does have its drawbacks over certain synthetic materials. Goose down when wet has almost no insulating qualities. While it has “loft”, which means it expands to provide air pockets that are essential to maintaining warmth throughout the night, the down is easily compacted causing cold spots unless the bag is a high enough quality to where the down is in individual pockets inside the lining. The pockets keep the down from spreading thin as you lay on it.
Down filled bags must be dried properly and not stored rolled up to prevent compacting the down. It would be necessary to have a waterproof sleeping bag cover or Bivy, which can act as a shelter if you do not have a tent to protect you from the elements. Once the down becomes wet, it must be dried before storing. Most experts would agree sleeping with wet down in cold weather is more dangerous than sleeping without the bag at all because anyone sleeping on damp material can easily succumb to hypothermia.
A synthetic material such as PrimaLoft® is a microfiber thermal insulator that provides close to the same insulating qualities as down. PrimaLoft was developed specifically for the United States Army in the 1980s. The material is comparable to goose down but it does not lose its insulating qualities when wet and is easily dried and can be stored rolled up tight. Additionally it is considerably less expensive than goose down.
The material does not compact like goose down so it reduces cold spots and can provide more cushioning against the ground. However, with any sleeping bag it is recommended that you use a sleeping mat to providing cushioning and insulation because sleeping bags simply do not provide much protection against the ground.
The bag of course must have a zipper that allows opening from inside the bag. The zipper area should be reinforced with a draft tube along the zipper so there is not a “cold zone”.
The bag should come with a water resistant if not waterproof carry bag that can be lashed to your pack to keep the bag dry during rainy hikes. The sleeping bag must be such that it can be rolled tight when not in use.
Know the climate in the area you will be hiking or camping in so you can be prepared. A bag that protects you at below zero will protect you at below zero and above but a bag rated between 32 and 50ᵒF could create a serious problem if the temperature drops below freezing.