Denali Half Bag

Camp down to -13°C and bivvy down to -22°C.*

Expedition half bag (pied d'elephant) to insulate legs and feet. Combine with suitable expedition down clothing to save weight and reduce pack-size. The use of pied d’elephant or Halfbags for lightweight bivis and camping is well proven in the mountains. Here we’ve added a hooded fabric “extender” to cocoon your body, arms and hands to reduce cold air ingress.

A half-bag is a specialized, minimalist shelter designed for fast and light mountain expeditions where weight and space are at a premium. Unlike traditional sleeping bags or full bivvy sacks, a half-bag only covers the lower half of the body, protecting the legs, feet, and lower torso while leaving the upper body to be covered by the insulated jacket you already have. This design is particularly useful in the mountains, where mountain climbers and trekkers often rely on a combination of lightweight gear and layers for warmth.

For mountain adventurers, a half-bag provides a combination of protection and mobility. It allows for quick setups and pack-downs, essential for high-altitude expeditions where time is critical, and conditions can change rapidly. It’s an excellent option for those tackling fast routes or summiting peaks where the weight of a full sleeping bag can be a burden, yet some degree of shelter and warmth is needed. 

The logic behind half-bags is simple. If you're wearing a warm jacket already, all you need to spend the night out is something to keep your legs warm and there's no lighter way to do that than to use a half-bag. Check out the weights of PHD's half-bags and see for yourself.

Here with the Denali we’ve added a hooded fabric extender to cocoon your head, upper body, arms and hands to cut cold air drafts.

• Deep winter bivvying and snow-holing when paired with a suitable jacket
• When you want to wander along your route, free to sleep under the stars as the fancy takes you
• When you want a lightweight backup in case weather, miscalculation or accident catch you out

...A half-bag is the lightest answer.

The optional waterproof Dri-LX outer provides an extra seam-sealed outer shell to the bag. While a shelled half bag is not designed to be used alone in heavy rain (water will find its way in) the shell does protect the bag when it is used outdoors without a tent, for example in a snow-hole or under a tarp.

*Note on Temperature Ratings

We have given two separate TOTs (Typical Operating Temperatures) for this half-bag.

• 'Camp' is for the times people might want to use it for lightweight camping instead of taking a sleeping bag (an appropriate jacket and ground insulation is assumed): this is a standard TOT, meaning you should be able to get a good night's sleep under normal circumstances.
• 'Bivvy' gives a range of temperatures from the usual doze level down to the point beyond which you're liable to be awake and getting cold. Again an insulated jacket is needed.

All these figures assume you are wearing normal clothing inside the half-bag. Any insulated kit like down trousers and down socks will improve the TOT. Don’t forget, the down jacket needs to be warm enough to sleep in.