Lightweight Backpacking Gear for Cold Winter Temperatures (Two-Layer Systems, Vapor Barriers, and Really Puffy Stuff)

Introduction

Cold hands and feet, and a chilly night’s sleep are the most common complaints we hear from participants in our guided winter treks and skills courses.

Ultralight backpackers are well-known for adding back tenths of ounces to their kits in the interest of making incremental (and often, inconsequential) improvements to their safety and comfort.

When temperatures drop way below the freezing point, a different mindset is required:

• What packs a lot of warmth for its weight?
• What sort of innovative combinations can we use to improve comfort and performance?

If I’m thinking about extending my three-season kit into very cold winter temperatures, I start thinking about three important strategies:

1. Two-layer insulation systems
2. Vapor barrier systems
3. Really puffy stuff

Two-Layer Insulation Systems

I like to use two-layer insulation systems where the outer layer is synthetic and the inner layer is down.

Down offers the best warmth:weight ratio for the inner layer. Synthetic insulation may be useful for the outer layer to concentrate the condensation (dew) point away from the down to maintain the integrity (loft) of down insulation on a multi-day trip. This works best with a sleep system. I discuss this two-layer system more in the Inclement Conditions Masterclass.

My current cold-weather sleep system uses an ultralight 20 F inner bag (Feathered Friends Tanager CFL 20) and an outer 50 F synthetic quilt (Enlightened Equipment Enigma Apex).

Another option to consider is separate high-loft synthetic insulating layers for active use (like the Patagonia Nano-Air Light or Arc’teryx Proton LT), which expel moisture better and are more breathable, and more traditional (down) insulation layers at rest and in camp. Layer both when temperatures plummet after sundown.

Vapor Barrier Systems

I use vapor-barrier (VB) clothing inside my insulating layers to prevent moisture emanating from my body entering the down in the first place.

I’ve had good success with the Stephenson shirt which can also be used for swanky outdoor winter parties because of its timeless 1970s style. More practical designs are available from RBH, and I’ve had excellent success with all of their clothing through the years. The jacket and pants are important components of the clothing and sleep system I use for multi-day mid-winter ski expeditions, including one where I used a bivy sack for my shelter in Montana’s Lee Metcalf Wilderness where temperatures plummeted to -30 deg F.

The Forty Below Vest doesn’t offer the complete warming benefits of a full VB shirt, but it does keep my back dry while wearing a pack in the winter. Back sweat is the primary reason for that wintry flash-off chill you get when you take your pack off for a break (flash-off is the extreme chilling that occurs when your body heat is sucked away as it’s allocated to evaporate that sweat). RBH also makes a VB vest.

Vapor barriers work well for sleeping bag liners in arctic conditions. The Gryphon Taurus VRB approach is the lightest and simplest way to achieve it (it uses aluminized Dyneema as the integrated vapor barrier liner).

I also like vapor barrier liners in mittens. Hardcore ultralight hikers like to use disposable latex, nitrile, or food prep gloves under their insulating gloves, but these aren’t items durable enough for winter expedition travel and are terribly uncomfortable. Check out the RBH Designs Ultralight Mitt, a staple I bring on all of my multi-day winter trips.

Vapor barrier socks are a no-brainer for footwear – even if they are semi-permeable. I use Rocky Gore-Tex socks and write extensively about them here. RBH fleece socks (with an ultralight merino liner sock) are my favorite combination for extreme cold while wearing my current winter lightweight hiking shoes and Forty Below Overboots on snowshoe trips, or with my leather backcountry ski boots.

Really Puffy Stuff

Max has an idea of what he thinks is needed for serious winter warmth in a parka, and it’s hard to argue with him. My personal favorites are the current PhD Yukon Pullover K (we reviewed an older model here) and the Feathered Friends Helios. I like puffy pants as well, and my choice are the WM Flights.

But how about puffies for the hands?

If you’re on a budget, suffer from cold hands, and need as much warmth as possible for as little weight as possible, then the Outdoor Research Transcendent Mitt is hard to beat.

However, you’ll need to follow a few tips to get the most performance out of them:

1. The Transcendent Mitts are for c-c-c-old temperatures –  well below freezing. They aren’t made with waterproof materials, so rain will soak them and they will be very hard to dry out.
2. I use these only at rest stops and in camp hanging out doing nothing, or while hiking in an emergency. They are that toasty. Keeping my hands warm while moving is usually not an issue for me. When I tried these during high-aerobic activity (fast hiking, carrying a heavy pack, and snowshoeing/skiing) at temperatures near zero, my hands became very sweaty in them.
3. Sleep with them in your sleeping bag (as long as they aren’t too wet), so any accumulated condensation in the mitt will dry by morning (and the condensation will be transfered to the outer synthetic bag layer, if you are using a 2-layer sleep system as described earliier).
4. They work best with glove liners – something like a really thin wool or fleece fingered glove. That way, when you need to perform an activity requiring dexterity (like lighting a stove), just pull your liner-clad hands out of the mitt and you have enough insulation on your fingers even if it’s cold, wet, and windy to perform fine motor tasks for a short duration.
5. They are too fragile to be a “work glove” (e.g., a ski, firewood-collecting, or bushwhacking glove).

Puffies are available for the head, too. Nunatak and Enlightened Equipment offer very light options that pack a ton of warmth for their weight. My favorite feature of a clothing system that uses a balaclava (or a hooded puffy jacket, for that matter) is that I can still use hoodless bags in the winter, which (for me) are more comfortable than trying to roll around in a hooded mummy bag.

Conclusion

Staying warm in the winter isn’t easy but it’s not rocket science, either. It does require a multi-faceted skillset that considers everything from managing your exertion levels to food, nutrition, and hydration to your choices for cold-weather clothing, sleep, and shelter systems.

Three strategies for getting the most performance (and versatility) include:

1. Two-layer insulation systems that combine synthetic and down layers for insulating clothing and sleeping bags;
2. Vapor barriers in sleep, clothing, handwear, and footwear systems;
3. Maximize warmth-to-weight ratios by selecting really puffy products – high loft (fill-power) down combined with ultralight shell and lining fabrics.

Disclosure

Updated November 7, 2011

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