If you were lucky enough to tune into the Discovery Channel’s Man vs. Wild during its heyday, you might’ve witnessed Bear Grylls, a former British Special Air Service operator and the show’s host, make TV magic by gutting a dead camel and demonstrating how to climb inside the carcass for warmth and shelter. The sequence of teeth-clenching footage is perhaps the best reminder that hey, sleeping bags are pretty cool.Sleeping bags are a camping essential, and even those of us who never bed down under the stars typically keep one around the house as emergency bedding. We tend not to upgrade our sleeping bags with the same frequency as other pieces of outdoor gear, like hiking boots or down jackets. But sleeping bags have come a long way in the past decade. This guide, which we’ve organized by fill type and temperature rating, represents the best of the current class. Here's how to choose the best sleeping bag:
Every sleeping bag comes with a temperature rating, usually represented, roughly, by a number in its name. That number comes from third-party lab testing. Those labs test for two numbers, a comfort rating, and a lower limit rating. The former is the environmental temperature in which a sleeping bag can provide sufficient warmth for colder sleepers; the lower limit rating represents the temperature at which a warm sleeper will be comfortable. The number in a sleeping bag’s name may not be its exact temperature rating; brands tend to round numbers to the nearest five or zero. For example, REI’s Trailbreak 30 has a lower limit rating of 29 degrees Fahrenheit and a comfort rating of 38 degrees Fahrenheit. Also, sleeping bags with lower temperature ratings typically use more material, so they will be bigger and take up more space in a backpack or closet.
Should You Get Down or Synthetic Insulation?
Sleeping bags provide warmth by trapping air inside their fluffy filling, which is typically either down or synthetic. Choosing which is right for you is a matter of pros and cons. Down, which comes from geese and ducks, tends to provide more warmth in a smaller volume than most synthetic insulation. Down insulation comes with a fill rating that denotes its quality. For instance, a 30-degree sleeping bag with 800-fill down will provide the same amount of warmth as a 650-fill bag rated to the same temperature, but it will do so with less insulation, so it will pack down smaller. Down’s main drawback is that it clumps when it gets wet, but many brands today use down that’s treated to be water-repellant. Down sleeping bags are also almost always more expensive than synthetic ones.
Synthetic insulation consists of manufactured fibers that attempt to mimic down. Synthetic insulation tends to be more water-resistant, durable and affordable but also bulkier and heavier.
Depending how often you use it, a sleeping bag can last you for years; it’s a long-term investment. Sleeping bags are also expensive, and their price is a product of the materials used. As a rule, down insulation is more expensive than synthetic, and higher fill powers (more warmth for weight) are more expensive than lower ones. Because they use more material, cold-weather sleeping bags tend to be more expensive than warm-weather sleeping bags.