A sleeping bag buyer’s guide:

If you’re seeking the ideal sleeping bag that will meet all of your outdoor needs, forget it! There isn’t such a beast. However, there is a bag out there that will keep you snug and happy through most of your adventuring dreams — a three-season mummy with a temperature/comfort rating of around 10 to 20 degrees Fahrenheit.

A good three-season bag should see you through a frosty evening in spring or fall and not overheat you during a warm night in July. If your inclination is more to winter camping, then opt for a bag rated to below 0 degrees Fahrenheit. Winter mountaineering requires temperature ratings of minus 15 to minus 40 degrees Fahrenheit.

Mummy-shaped bags are more efficient at keeping the body warm. However, some people find them constricting. Also, be sure that if you are buying bags to zip together, the zippers are compatible and you purchase a right and left zipper. The other choices of shape are semi-rectangular and rectangular (see Figure 1).


Figure 1: Mummy (left), semi rectangular, and rectangular sleeping bags.

Most bags are constructed of nylon, polyester, or nylon blends inside and out. Sleeping bags with cotton insides, quilted rectangular shapes, and Pokémon or other entertaining figures printed on them, not surprisingly, they re not recommended for backpacking or remotely serious outdoor use.

When you buy any sleeping bag, take the time to “kick the tires.” Climb inside each one, roll around, zip it up, stuff it, unstuff it, compare lofts, and then choose the one that seems to best meet your needs for space, warmth, and features.

All sleeping bags need some of the same general features. Check out the following:

  • A lining of taffeta or other soft non-cotton material is more comfy, warms quickly, and breathes supremely.
  • A two-way zipper offers more ventilation and flexibility options. Be sure to buy a right- or a left-side zipper that is compatible with the other bag if you desire companionship.
  • You want a differential cut — the inner lining is sewn smaller than the outer shell — which allows insulation to loft to its maximum. If there is more loft, there is more warmth.
  • An insulated draft collar helps to seal in the warmth and keep out the cold around your neck and shoulders.
  • Hook and loop tabs cover the zipper toggle by the hood, preventing unplanned unzipperings whilst you slumber.
  • A multi sectioned or shaped hood cups the head naturally.
  • Ample draft tube that hangs from the top of the bag and covers the zipper to seal out cold air.
  • A windproof and water-resistant outer shell. DryLoft is the most downproof.
  • Semi rectangular cut for sleepers who toss and turn. Mummy-style bag for sleepers who manage to stay put.
  • Dark coloured lining. This absorbs heat better and the sun’s rays most efficiently should you need to dry out your bed.
  • One last highly desirable option: a fleece-lined stuff sack. Turn it inside out for a comfy pillow when stuffed with a parka or your extra clothes.

Bags for cold nights:

Sleeping bag designers generally agree that a cold weather bag must have the following features to keep the occupant really warm: zipper draft tubes and shoulder collars, hoods that cup the head and insulate without being claustrophobic, and a temperature rating of 0 Fahrenheit or below (in the winter it is far better to err on the side of warmth).

What insulation do designers prefer? Down, with a 650-power fill rating or above, is best for weight-to-warmth ratio and for longevity. The fill power of down indicates the amount of actual downy feather and quill. The lower the fill number, the more quill and less feather. The higher the number, the less quill and more feather.

How big should a winter bag be? Buy it long. Most mountaineers recommend against regular-sized bags and opt for bags that offer at least an extra 8 to 10 inches of space at the foot after you are nestled comfortably inside. Those extra inches provide adequate space to store cameras, water, boots, and such items that you don’t want to freeze. In addition, bags with a wider cut can offer more warmth because they give you room to add clothing without constricting the bag.