Camping. You won’t carry an outfit very far, at most — from the parking lot to the shore of the lake. It should meet only one principle — comfort. Camping bags are often roomy, have a lot of nice, but not the most indispensable options, can unzip completely, turn into a blanket. They are barely applicable for other activities.

They’re also soft and comfortable, thanks to a 20-denier taffeta nylon shell and lining. You get a cosy hood and a ‘natural fit’ footbox to give your toes a bit more wiggle room. In addition, features like a zipper draught tube with an anti-snag zipper design and a lofty draught collar help to keep things extra toasty. Those are design elements usually only found in much higher-priced bags. The fill weight is literally how much just the down weighs in a bag. In this case it’s less than half the weight of the bag, which indicates the bag has burly fabric and zippers. It also makes for a colder bag — if the fill weight were higher it would be warmer. The Lower Limit means this bag will technically be comfortable to 19 degrees. However, through our tests “comfortable” isn’t really the word. Survivable is the word. This is a common issue with sleeping bags and the EN testing system, and we feel the rating should be higher. More on sleeping bag EN testing in our guide. TIP: Don’t opt for a sleeping bag that offers less insulation than you might need just to save a few measly ounces/grams. As mentioned above, it’s always wise to choose a bag that will have you covered in temps at least 10 degrees below those you expect to encounter, and if this means opting for a bag that’s slightly heavier than you’d ideally like, then we’d recommend you bite the bullet and buy it regardless. Insulation Type What we like: A budget design that’s a step up in build quality from the Coleman and Teton Sports bags above.Sliding into a fluffy sleeping bag after a long day of hiking is one of the most satisfying experiences on the trail. The daytime is meant for traversing ravines and climbing mountains, but at night all a weary explorer wants is to shimmy into a warm cocoon and catch some Zs, swaddled snugly in a cozy cloud like a little angel baby.

The Cosmic Down 20 uses a traditional mummy-style shape with a substantial footbox and very practical hood that can be cinched down over your face on particularly cold nights. The tapered design maximizes thermal efficiency, leaves little room for drafts, and not a great deal of extra space for you to warm up with your body heat. Beware: this bag may not prevent cold feet. If you go in knowing this and bring the right layers, you should be fine in most temperatures down to freezing. Durability 4 Stars The Cosmic Down has put on some weight over the last year, going from a reasonable 2.71 lbs to currently 3.4 lbs, and is among the heaviest of the down bags we tested. While most down bags boast a great warmth-to-weight ratio, we are disappointed by its weight. Once competitive with other bags in weight and price, this latest version is now only competitive in price. The Cosmic Down 20 is offered in a men’s bag in three sizes, and one size for women. The main differences are length, and the women’s bag is warmer (and shorter) overall. We tested the Regular.

The three main types of insulating fill in modern sleeping bags are down, water-resistant down, and synthetic insulation. Each of these fill types has its advantages and disadvantages, all of which we’ll cover below Mummy bags typically have a ¾-length side zip that requires some wriggling to get in and out of and can’t be opened up completely should you want to zip the sleeping bag together with another compatible bag. That’s why for camping, we prefer a bag that fully unzips. Not only is it easy to create a large and comfortable space for two if you zip it to another bag, but unzipping the bag on its own opens it up for use as a blanket. And if the bag has a tough exterior shell, you can use it as an outdoor picnic blanket in a pinch. We prefer a full zipper for camping

If you know you "sleep cold" or have plans for colder trips in the spring or fall, the Western Mountaineering UltraLite is the bag for you. With 17 ounces of 850+ fill power down and a legit draft collar, this is the warmest bag in our test. Our cold-sleeping lead tester used it at 12,000 feet in October and had no problems staying warm. At the same time, its full-length zipper and horizontal baffle construction provide ample options to shed heat and cool off on warmer nights. We slept comfortably in this bag across an expansive range of overnight temperatures from 10° to 55°F. Got all that? Great! Then let’s get down to business will our review of the Kelty Cosmic Down 20. Warmth As a general rule, we’d highly recommend choosing a bag that has a comfort rating at least ten degrees below the lowest temperatures you expect to encounter on your trips—heating up in a bag that doesn’t offer enough insulation is very difficult, whereas cooling down in one that has a little too much insulation is very easily done (use the zippers!).

Size

In short, the ability of down to provide insulation is measured by its fill power, which is usually given as a number between 400 and 900. This refers to the number of cubic inches one ounce of down will fill when it has reached its maximum loft. The low end of acceptable down fill power for sleeping bags. The DriDown means it is treated to be hydrophobic (water resistant). More on sleeping bag insulation types in our Guide.