In winter travel, physical suffering, mental hardship, and discomfort are a constant. Danger does not need to be. While COVID has canceled the Antarctic season, winter 2020 could still see some extreme cold-weather expeditions. ExplorersWeb spoke to some cold-weather experts about how to survive the four main perils: cold, wind, thin ice, and deep snow.
Deep Cold
Cold is relative. I live in Vietnam, where cold is anything below 24°C. For polar travel, temperatures of -20°C might be considered relatively warm and pleasant.
On the Antarctic ice shelves on a calm, sunny day, temperatures below -25°C might only require a base layer. The exercise needed to keep your sled moving stokes enough warmth to offset the chill. Higher up, on the Antarctic plateau, fierce polar winds require 100 percent cover, even in sunshine.
Antarctica can feel surprisingly warm on a sunny day. Photo: Jenny Davis
So, what constitutes deep cold? Polar adventurer and guide Eric Philips explains that travel becomes significantly harder below -25˚C, but perhaps not for the reason you think. The approach to temperature remains the same: Expeditioners trying to balance staying warm with not sweating. The added difficulty comes from a subtler change.
-54°C definitely classifies as deep cold. Photo: Jerry Kobalenko
Normally, when skiing or pulling a sled, friction creates a micro-thin membrane of water beneath the runners, helping you glide forward. Below about -25°C, this membrane does not form. The science behind this phenomenon is not set, but in theory, the ice crystals at lower temperatures firm up, gripping onto your sled and skis, impeding progress. The lower the temperature, the more difficult hauling becomes. A long cold snap makes progress much harder and slower.
Our editor, Jerry Kobalenko, regards deep cold as below -40°C. This is when the temperature needs the most care and presents the greatest danger. While -20°C might allow a more casual traveling style, -40°C forces you to behave more like an astronaut than a camper. You need to use your quality gear precisely. You keep moving, no sit-down breaks. He follows the Five-Minute Rule, restarting before exercise metabolism cools down. If it does, it takes a painful half-hour to warm back up again. Fingers numb out, then become painful when circulation returns and the impurities are reabsorbed. Ice climbers refer to this as the screaming barfies. According to one study, 96 percent of ice climbers have experienced this, and 4 percent of those have thrown up!
Bent over almost double, author James MacKinnon hauls across the unsettled snow of a Labrador lake. Photo: Jerry Kobalenko
For long-distance haulers, putting on cold boots each morning is painful and can lead to numb feet for several months after the peripheral nerves die off, which happens when surface skin temperature drops below 9°C too often. Worse is frostbite, an actual freezing of tissues, in which cells rupture when ice forms in them. Philips protects himself and his clients by adapting all his kit to be usable without removing mittens. This means choosing mittens that allow maximum dexterity as well as adding loops to all zippers.
Wind
Wind and cold go hand in hand. In discussing cold, people like to cite windchill equivalents (which are exaggerated) rather than actual air temperatures because it makes their feats sound more extreme. But windchill is genuinely dangerous.
Lou Rudd hauls into grim whiteout conditions in Antarctica. Photo: Lou Rudd
On the Antarctic plateau, winds can exceed 300km per hour. Here, any exposed skin quickly freezes. One hundred percent coverage is needed. This means base layers, a shell jacket, an appropriate ruff, and goggles. But 100 percent cover creates a new problem, exhalation. When we breathe, we produce warm, moist air. Wearing a face mask in extreme cold deflects your breath, which freezes onto the mask and ices up sunglasses and goggles, making navigation almost impossible. You can’t forego eye protection because of the threat of snowblindness.
There is no easy fix. Norwegians typically hang a drape-like mask to the bottom of their googles. This ensures 100 percent cover, but Philips is not a fan, as he finds that his breath quickly frosts up his googles. He prefers instead a high face mask, goggles, and a nose cap.
A pair of well-ventilated goggles is essential. Philips uses a design that lets him pull the lens off the frame, which allows airflow and clears the fog. He also uses a breathing technique a little like a swimmer, breathing down and outward. He has become so used to this that he finds himself doing it at home when wearing sunglasses.
-40°C with a 30-knot wind; no travel in that. Photo: Jerry Kobalenko
Wind direction is also important. A strong headwind makes hauling so inefficient that it is better to take a rest day than to exhaust yourself for a handful of kilometres. You can get away with more in tailwinds, though setting up camp at the end of the day is challenging. For a solo trekker, in open country with a dome tent, it may be impossible.
Managing your energy is vital on long-distance treks. For this reason, Philips cautions that you should not underrate sleep. When he guides, sleep is his number one priority. He aims for eight hours every night.
Thin Ice
There are two types of thin ice, freshwater and sea.
For those heading to the North Pole, thin sea ice has traditionally been a major problem. When seawater freezes, it forms a greyish layer called nilas. Nilas is more flexible than freshwater ice — it flexes like a rubbery membrane, a weird feeling — but is generally safe to ski over. When judging whether ice is safe to cross, color is key. The darker the ice, the more likely it is to break.
Melting sea ice. At first, firm ice underlies those shin-deep pools, but it thins out as summer progresses. Photo: Jerry Kobalenko
When approaching a frozen lead in the Arctic, Philips first examines the color. Sometimes, however, the ice is covered with frost flowers, the result of salt freezing into carnation-like shapes. A spot of cleaning is required. He uses a ski like a windscreen wiper to scrape away the frost flowers to properly assess the color of the ice. Next, he pokes the ice with a ski pole. If the ice seems firm, he takes a single step. Next, a heavy stamp. If there is still no breakthrough, he puts both skis down but stays close to the edge for safety. Slowly he advances out a couple of metres, without his sled. Finally, he takes the sled with him, and if the ice doesn’t begin to give way or pool with water, then it is safe to cross. Despite this cautious approach, he wears a drysuit, just in case.
Thin freshwater ice is much more brittle. A couple of inches is usually safe to cross, and the strength can also be partly judged by color. Greenish or greyish ice spells trouble. As well as visual cues, listen for the sound of running water beneath the ice on creeks and rivers. If you can hear something, the ice is too thin. High Arctic rivers are shallow and braided and tend to freeze right to the bottom, but larger rivers further south may be open around rapids.
A sledder skirts disturbed river ice in the subarctic. Photo: Jerry Kobalenko
Deep Snow
The bane of every Antarctic hauler in 2018, deep snow is more obstacle than danger. Forcing a path through powder is extremely aerobic. Depending on the weight of the sled and the depth and softness of the snow, you may have to pause to catch your breath each 100 steps, or 50, or 20.
Laval St. Germain enjoys a refreshing aerobic workout in the soft snow near Hercules Inlet, Antarctica. Photo: Laval St. Germain
Snow messes with your routine at night too. Although tunnel tents are better in a wind than dome tents, if the wind shifts and starts hitting the long side, drifting snow can quickly bury you. You must periodically rise and dig yourself out before the tent is engulfed.
Snowshoes are better than skis in deep, soft snow. You may need to unclip from the sled, break trail with your snowshoes, then return to haul, making just one kilometre forward for every three kilometres of work. On one winter expedition, Kobalenko and his partner made only a kilometre per hour for a month. That’s when the polar sledder’s most important quality, patience, is sorely tested.
