Finding a Sleeping Bag

Selecting the right sleeping bag can be an exciting task. Decisions on size, shape, type of insulation, loft and temperature rating must be made. The type of sleeping bag you purchase depends primarily upon what level of warmth and dryness you’ll need to sleep comfortably.

Types of Bags
For most people, the primary goal in buying the right sleeping bag is to find the warmest, yet lightest, bag for your intended use.

• Backpacking bags are designed for general recreational conditions with a wide comfort range for varying temperatures. They are rated for the most comfort between +10 degrees and +40 degrees Fahrenheit. They are generally a modified mummy shape and feature both down and synthetic insulators.
• Winter/expedition bags are the choice for expedition climbers, winter campers and backcountry skiers. They are usually the heaviest and warmest bags available. The comfort rating falls between -40 degrees and 0 degrees Fahrenheit. They are almost always a mummy or modified mummy shape, to retain the greatest amount of body warmth in extreme conditions.
• Camping or recreational bags are designed for general use in moderate temperatures. Temperature ratings fall between +35 degrees and +55 degrees Fahrenheit, and the bags are almost exclusively made of synthetic insulation. Shapes are most often rectangular for comfort and
  width. These bags tend to be heavier and less easily compressed.
• Children’s bags are designed especially for their smaller body sizes, and come in all shapes except mummy bags. Generally, they are made with synthetic insulation.

Temperature Rating

Before purchasing a sleeping bag, consider the nighttime temperature range in which you’ll be camping. Bags are categorized by a “temperature rating,” which indicates the temperature in which the bag will keep you warm. A bag marked 10Þ will keep you comfortable in 10 degree weather, while a bag marked -20Þ will leave you sweating during summer trips.

Because warmth is subjective, there are no standard measurements of temperature ratings among sleeping bag manufacturers. The temperature at which a given sleeping bag should keep the “average person” is also subjective. Some people sleep warmer or colder than others. Your sleeping habits should be a primary factor in the selection of your bag’s temperature rating.

Fill (Insulation)

The insulation affects warmth, durability, care and cost. There are two main types of insulation: goose down and synthetics. A natural insulator, goose down compresses more and is lighter (a significant consideration if you’re carrying gear a long way) than synthetic materials. Down is the best of all insulating materials, and is a natural fiber that will last longer than synthetics. The only drawback to goose down is that is virtually worthless if it gets wet, because it absorbs moisture readily and takes a long time to dry.

However, although down bags can be more expensive, they will last a lifetime if cared for properly.

Look for the Fill Power Rating on these types of sleeping bags. This refers to an industry test which measures the volume of 1 oz. of down. The higher the fill power, the more loft with less weight.

In contrast, synthetics are usually heavier than down bags of the same temperature rating.However, they are less affected by moisture and will perform well when wet. Synthetic insulation is the #1 form of fill in bags.There are several fiber options available Polarguard® 3D is considered by many to be the top synthetic for its durability and weight. A continuous filament fiber which doesn’t shift or mat. Polarguard® HV, the predecessor to Polarguard(R)3D, and Thermolite® Micro, are also valued by many for its warmth, durability and loft retention.

Loft

Loft is what actually keeps you warm. It describes the amount of air that is trapped inside your bag.
Down bags usually have a higher loft than synthetics.

Shapes

There are three basic shapes of sleeping bags: mummy, semi-rectangular, and rectangular.

• Mummies are very close fitting, efficient, hooded bags that save packing space. The drawback is the sleeping space is very small, which can make it tight and uncomfortable. They are used predominately for winter/expedition bags and backpacking bags.
• Semi-rectangular bags are wide in the chest and hip areas with slight tapers at the foot-sack and head. Not as warm as mummies, they take up more space, but provide a little more maneuverability and generally come with hoods for flexibility. They are frequently used as versatile, three-season bags.
• Rectangular bags are designed for warmer weather. They let lots of heat escape and are very bulky and heavy. However they are versatile and provide a lot of space to move around in. They are primarily used for light camping excursions.

Bag Length

Most bags come in regular and long lengths. Look for sleeping bags that match your body size at the shoulder, hip and foot. A bag that’s too big will let more cold air inside, so if you’re on the short side, stay away from longer sizes. However, a bag that’s too small won’t allow you to move around comfortably. The size also affects how much space the bag takes when packed.

You may want a longer bag for colder conditions such as mountaineering or winter camping. You can use the extra space for boots, a water bottle and other equipment you want to keep from freezing overnight.

Many manufacturers now offer bags that are designed specifically for women. The bags are a bit shorter and less tapered at the hips to allow for a more thermally efficient fit. In addition, some women’s bags contain extra insulation around the torso and feet.

Shell

With most bags, the shell that covers it is made of a Ripstop nylon that is highly durable, breathes well and resists wind while providing modest moisture protection.

Sleeping Pads

A good sleeping pad is critical for comfort and will help you take advantage of your bag’s warmth. The insulation material, or “fill” on the bottom of the bag is compressed when you lay on it, and the bag loses the loft that keeps you warm. A pad is necessary to give you the insulation needed to protect you from the ground, which is always colder than body temperature.