In an alpine environment, it is essential to be able to stay warm and dry. Depending on the season, location, length of route, and altitude your layering options will vary slightly; though in most cases, the layering system will have a similar process. In the book, Extreme Alpinism, Mark Twight coined the term ‘action suit’ to refer to a simple layering system that can be functionally worn on the approach and on the climb. This action suit is a versatile system allowing a climber to exert energy on the approach/climb without developing moisture buildup and quickly retain the heat the body has developed to stay warm at a belay or rest. Use the following guideline to build the appropriate system for you, based on how much heat/energy you expel on a climb and where you plan on climbing.
- Base layer: Wool works by absorbing moisture into the fabric and using the body’s heat to encourage evaporation. Synthetics are hydrophobic and will force moisture to the exterior of the fabric. Merino wool has natural antimicrobial properties, so you won’t stink (as badly) after multiple days of sweating into the same clothes, whereas synthetics use aluminum to reduce the stink factor. In an alpine environment where temperatures fluctuate by the minute, it is critical to always have dry fabric against the skin and the quickest drying fabric available and unfortunately merino wool is often not a satisfactory base layer in an alpine environment. The 1/4 long sleeve zip with a high collar is great, because you can dump heat by unzipping the shirt or zip the collar all the way and pair it with a buff to block the sun/wind.
- Mid layer: A midweight pullover is a great lightweight layer that offers huge versatility. The Patagonia R1 Hoody is a favorite, with a deep front zip, long collar, and tight fitting hood that can be worn under or over a climbing helmet. This layer should be light but warm.
- Wind shirt: The windshirt should be ultralight and have a DWR coating. This jacket (or pullover to save weight) should be no frills and and without insulation. It can be used as an emergency rain shell on one-day climbs or as a protective layer when a full shell is unnecessary.
- Softshell jacket: Choose wisely because this layer will likely be the most important piece of gear on a route. Unless you are climbing in very cold weather, this softshell should not be insulated. The benefit of a softshell jacket is the great breathability and durable outer material. Most modern softshells can take the place of a hard shell in dry locations such as the Wasatch Range, Colorado, Denali, etc. When purchasing a softshell, look for lightweight models with high breathability and waterproof ratings.
- Hard shell: If you’re climbing in the Pacific Northwest or approaching a high altitude climb that has a trek through the rainforest to reach the base, this layer may be appropriate. A hardshell need not be heavy or insulated, often a simple 3 layer membrane shell with high breathability and waterproof will suffice. Gore Tex certainly has a strong reputation, though newer brands such as EVent or Mountain Hardwear’s proprietary DryQ Elite are making a splash in the market and are definitely worth checking out. Don’t start off with the hardshell on as you will likely overheat too quickly, but if the wind is strong or it’s precipitating this layer can be used.
- Belay parka: The main source of immediate warmth when stopped at a rest or belay. This parka needs to be appropriate for the worst conditions to be encountered with consideration for the amount of time being stopped. A down jacket will provide the most warmth for the least weight and is more compressible than a synthetic alternative. Choose a lightweight parka that can be thrown over all your layers and retain the heat your body had produced up to that point. Key features include a beefy front zipper that slides smoothly, 1-2 large interior water bottle pockets and a napoleon pocket to stash snacks for easy access at breaks.
- Base layer: A lightweight base layer can add significant heat overall and may only be warranted on cold weather climbs. It is too difficult to add/remove a baselayer once you leave camp, so decide whether this layer is needed.
- Softshell pants: As with the softshell jacket, this layer is the go-to layer for most conditions. Depending on the season of use, these pants will vary in thickness. Look for a pair of mid-weight softshells with a brushed inner face and reinforced insteps, such as the Patagonia Alpine Guide or Arcteryx Gamma pants.
- Hardshell pants: In wet or windy conditions this layer may be necessary. Similar to the hardshell jacket, you likely won’t start in this layer, but may choose to put in on when the winds pick up or if the moisture increases (climbing through a wet/drippy icefall or approaching in the rain). Pants with full side zips allow you to put them on with boots/crampons still on as well as plenty of venting options. The hardshell pants can be put on over the harness, if you don’t need access to your gear loops, and the belay loop can be pulled through the front zipper (ex: non-technical mountaineering expedition).
- Gloves: Glove systems are going to depend highly on activity and temperature. On a non-technical high altitude mountaineering expedition there may be minimal dexterity and high warmth necessary, whereas on a winter alpine route, it may be necessary to have thinner, more dexterous gloves for placing protection, rope management, etc. The best advice is to learn to operate the necessary tasks in the gloves you plan to use on the climb. Beyond that, look for a glove system that allows different tasks to be completed while providing the necessary warmth.
- Hat: A helmet can actually provide a surprising amount of warmth and it is often overkill to wear a very thick WindStopper hat. Not only will an overly thick hat be too warm, but it also makes communication difficult, because your hearing is significantly muffled. A visor on the approach keeps the sun out of your eyes and it can be worn under a helmet if descending a mountain during the heat of the day. For warmth, a thinner toque or beanie can often provide enough warmth when layered under a helmet or with hood from the mid-layer. If windy conditions are encountered, pulling the outer layer hood over the helmet also increases the warmth factor.