Choosing a Sleeping Bag

Crawling into a sleeping bag that you know is going to be warm and comfortable is one of the singular pleasures of backcountry adventure. Just as a good sleeping bag can make for a good night's sleep, an ill-suited one can spell discomfort or worse.

Temperature Ratings

Decide where and when you're likely to use a bag. This will help determine if you need a winter, 3-season, or summer bag. Compare each bag's individual temperature rating. Ratings give a general idea of insulating performance and are a useful point of comparison. We believe our temperature ratings are realistic for most people in most conditions. Choose a warmer bag if you tend to sleep cold. We also have some tips on sleeping warm in our Staying Warm article.

Fill Type Comparison

For more information, please read about Down and Synthetic Fills.

Loft

Loft is a key factor in determining a bag's warmth. It refers to the thickness or puffiness of a bag. If two bags have the same fill type, features, and shape, the one with the higher loft will be warmer. For information on measuring a sleeping bag's warmth, see our article on Sleeping Bag Ratings and Standards Tests.

Shape

A sleeping bag's shape can dramatically affect its performance. It will also impact how comfortable it is to sleep in and how small its packed size will be.

• Mummy bags are designed to save weight and maximize heat retention. They narrow at the feet, flare out at the shoulders, then taper to a fitted hood. With less space for your body to heat, a close-fitting bag has superior warmth to weight than a roomier bag. However, some people find them too constricting.
• Barrel bags trade thermal efficiency for extra room. They have no hood, are slightly tapered, and incorporate a patterned oval foot section. They are slightly heavier and bulkier than mummy bags.
• Rectangular bags are suitable for warm weather, and are not the best choice for most backcountry travellers. Although inexpensive and roomy, they let a lot of body heat escape and are heavy and bulky for the insulation they provide.

Features and Construction

Hood and Neck Yoke

You lose 30 to 50 percent of your heat through your head and neck. A well-patterned hood is roomy yet contoured, and significantly increases a bag's warmth without adding much weight. The neck yoke is an insulated collar that covers your throat and shoulders. It reduces heat loss whether the bag is snugged down or loosely zipped. Some bags have a neck and muff combination that completely encircles the neck for additional warmth.

Footbox and Foot Oval

Feet and toes crush insulation. To compensate, mummy bags have square-shaped footboxes that allow for natural foot positions. The less-tailored equivalent in a barrel bag is called a foot oval. Extra insulation at the peak of the footbox or foot oval helps warm your toes.

Zipper and Draft Tube

Lefties generally prefer right-hand opening bags and vice versa. If you are planning to zip two bags together, ensure one has a right zip and one has a left zip. An insulated tube that runs behind the zipper to prevent heat loss is called a draft tube. Ideally, it is sewn only to the lining material, since sewing through the bag creates a cold spot.

Construction Methods

Sleeping bag construction methods vary in cost and the benefits each provide.

	Sewn-through is used in lightweight or warm-weather synthetic or down bags, it is inexpensive to construct, but can have cold spots at quilt lines.
	Offset Quilt is used for synthetic bags only. It has no cold spots at quilt lines and is less expensive than shingled construction.
	Shingles are used for synthetic bags only. It is the most warmth-to-weight efficient construction, but is more expensive than offset quilt.
	Baffles are used in down bags only. They feature mesh partitions at quilt lines to prevent cold spots and keep down from migrating through the bag. Expensive, but very warm.