Layering – A Versatile Approach for Extreme Cold Weather

It has been well established that layering is a superior approach for dressing for outdoor pursuits.  However, the traditional layering method of base, insulation, and shell often does not meet my needs.

I have spent a lot of time in the cold working out this method for layering, that allows for changing weather conditions, and changing activity levels.  I’ll separate the approach by torso and legs.

Here is a summary of the layers.

Torso

1. Base layer
2. Wind layer
3. Light insulation
4. Shell
5. Belay jacket (heavy insulation)

Legs

1. Base layer
2. Softshell
3. Belay pants

Base layer

The base layer is the start of the layering system.  It should fit snugly without feeling constricting, as the main purpose of the base layer is to keep your skin dry.  All your sweat should be wicked away from your skin to the outer layers where it can evaporate.

A common question is whether to use wool or synthetic base layers.  High quality merino wool base layers are available.  They are comfortable and good for some conditions.  Synthetics, I find, work better on extended trips.  I reviewed the wool versus synthetic debate previously.

Base layers come in a variety of weights, usually “lightweight”, “midweight”, and “heavy weight”. Sometimes, there is even an extra heavy weight.  For the most part, I stick with lightweight and midweight baselayers.  For the same conditions, I generally tolerate a heavier base layer on my legs than on my torso.  For example, I generally will wear a lightweight shirt, while choosing midweight for my legs.

Wind layer

No insulation on the back where a pack provides all the insulation you need. . . great design.

The next layer for the torso is the wind layer. The wind layer should be a very light wind shell, that is extremely breathable.  There really is no need for any waterproofing.  In fact, I don’t reapply (DWR) to my wind shells, as I have found they breathe more easily after a few washes.

The idea behind the wind layer is to allow all that perspiration to pass through, and then evaporate without chilling your core.  For this reason, I personally prefer a vest, as my arms seem to do just fine without a wind layer, so I see no need for the extra weight and reduced mobility of sleeves.

I reviewed the Marmot Driclime vest.

Light insulation

The purpose of the light insulation layer is purely to keep you comfortable (meaning slightly cool) while you are moving.  Carrying a pack, climbing, preparing camp, etc are all hard work and lots of insulation just isn’t necessary.

I have a variety of light fleece sweaters that I use depending on the overall expected conditions.  If temperatures will be above 0F much of the day, I’ll use a 100 weight fleece sweater or pullover if I need it.  Close to 32F, I am usually only wearing my base layer and my wind layer.  Below 0F, a 200 weight fleece sweater, usually fill zip with a hood is a good option.  For consistently severe cold, there are other options that can be lighter than fleece, such as thin synthetic insulated sweaters.  I tend not to use down for such a piece as it will get wet from sweat.  I also avoid the use of wool sweaters unless it is only a day hike.

Shell for the Torso

A shell jacket is still useful in extreme cold weather, however, it needs to be highly breathable.  Being waterproof is less of a necessity the colder the temperatures.  The likelihood of encountering liquid water is very low.  Wind resistance is critically important, as wide open and cold places tend to have very strong winds. Even light shells with DWR shed snowfall well enough.

I avoid the high cost waterproof breathable hard shells because my shell is going to get abused against rock, and there is a lot of risk of damage from ice tools, ice screws, and other sharp implements common in the cold.  And, as I mentioned, waterproofing isn’t a critical quality of a good extreme cold weather shell.

I’ve used the Marmot Precip jacket for years now in various forms.  It is a nice, light, and inexpensive option for a shell.

Belay jacket and pants

Leukotape patch on my DAS

The belay jacket and pants are common for winter climbing and mountaineering.  The idea is to have heavy insulation for periods without much movement.  These should be thick puffy garments full of synthetic insulation, as they go on over the top of all the sweaty layers from the day.

For the legs, full side zips are important so that boots do not need to be removed.  These garments must be sized to fit over the top of all of the other layers.

I discussed the belay jacket concept more thoroughly in the past, including my preference for the Patagonia DAS Parka and Patagonia Micro puff pants

Softshell for the legs

On my legs, I can tolerate one system much more easily because my legs aren’t full of critical organs that need to be closely temperature regulated.  In addition, I’m often wearing a climbing harness which precludes the ability to quickly, easily, and safely add or remove layers as conditions change.  These reasons lead to softshell being a more ideal system for the legs.

Softshell is suitable for a wide variety of conditions, more so than the traditional 3 layer system.  It is a light, breathable, and comfortable system.

I reviewed my favorite softshell pants, the Patagonia Mixmasters in the past.

Conclusion

The 5 layer approach for the torso, of base, wind, light insulation, light shell, and belay jacket, as well as the 3 layer approach for the legs of base, softshell, and belay pants works very well in a wide range of extreme cold weather and severe conditions.  I’ve used and abused this system for quite a while now, and have no reservations relying on it to keep me safe and comfortable in the mountains.

For more information about cold weather clothing choices, Extreme Alpinism: Climbing Light, Fast, and High by Mark Twight is a very good resource.

For more information about sleeping in the cold, see my article about cold weather sleep systems.

I hope this helps.  Let me know!

Tags: baselayer, belay jacket, belay pants, extreme cold weather, layering, Marmot, Patagonia, precip, wind layer