Words by Steve Sunny Whitfield
Years ago, I was on an expedition in the Kalahari Desert We had been trekking through 40 degree days, yet there we were all huddled together. Our team was wet and cold, shivering in sub zero temperatures thanks largely to an unexpected cold front and storm. It was a lesson to expect the unexpected but also a valuable lesson in layering.
Fast forwards a few years and I was on another expedition trekking through a tropical jungle carrying thermal underwear and a rain coat wondering if I should have brought my down jacket to the base of a high feature. Although it was a warm journey, we were approaching an attempt on a subzero summit. Talk about logistical planning!
Thus is the joy of expeditionary life. On expeditions you must cope with an array of climatic conditions and weather events, whilst also managing limited weight and space in carriage. So how can you prepare for every eventuality? The trick is you cant. But the answer to this temperature conundrum is layering.
The layering system is basic way of utilising clothes to ensure you stay protected in extreme condition (balmy or cold). Layering can utilise your clothes in ways that can limit your weight and maximise their efficacy. Two layers are often suffice for the lower body which means that often the layering system refers to the upper body in cold environments. When two layers are suffice below, you may need three or four above. Yet when you are on the move, less can mean more in terms of efficiency and warmth and whilst four layers can achieve protection, they can also make you overheat. So inter-changeability is important.
Three or four key layers that can interchange and fit on top of each other can actually replace the need for heavy garments. Although donning a jacket when things get chilly is appealing when you are stationary, when you are on the move, things can heat up rapidly, uncomfortably and dangerously. Layering can allow you to manage and regulate temperatures better whilst on expedition.
So what are the four basic layers?
- The base layer: Its chief function is to wick moisture away from your body during the day so keep it thin and absorbent.
- The thermal layer: This adds thermal insulation and is ideal for moving through the day
- The fleece layer: This is needed when the temperatures drop to 12–15 degrees, and great for nights
- The waterproof layer: This can also act as a windbreaker and serves you with vital protection. Its ideal for cold temperatures and acts as a housing for the other three layers.
Although every situation varies, and every expeditioner has their own personal preference, this structured approach to layering well covers most expeditions.
That said, these recommendations are nonspecific and rather elementary. Sourcing relevant weather information and equipment is essential, as certain layers work best for certain situations. The most sound advice recommends that you research the appropriate qualities of a layering system before acquire it, and local knowledge is always best.