cold and wet weather kit
selecting clothing and footwear combinations for use in cold and wet conditions
When I was 12, my parents bought me a neoprene jacket for a field studies trip. It was incredibly waterproof, although by the end of each day the inside of the coat was awash with streams of condensed sweat. So when, a few years later, I upgraded to a waterproof-breathable jacket, the difference in comfort was incredible. In the 1990s I found that even waterproof-breathables have their limits: high on the frigid slopes of Denali (North America’s highest peak), I wore uncoated windproof fabrics which remained flexible at minus 40ºC. By contrast, my climbing partner discovered that his waterproof-breathable jacket stiffened up like sheet aluminium as the thermometer plummeted.

These days there are thousands of possible outdoor clothing combinations which are designed to keep you as comfortable as possible in all manner of cold and wet conditions. Cotswold stock an enormous range of garments, and staff are on hand to discuss your specific requirements.

Paul Deegan

Paul is the author of the award-winning ‘The Mountain Traveller’s Handbook’, published by the British Mountaineering Council and available from Cotswold.
how waterproof's breathe'?
the layer system
There are certain misconceptions about how modern outer layers allow sweat vapour to pass through their fibres, a process commonly referred to as ‘breathing’.

On more than one occasion I’ve overheard mountaineers explaining to friends that wearing a ‘breathable’ jacket actually stops the user from sweating. Patently, this is not true! The key to understanding how most (but not all) waterproof-breathables work lies in an understanding that the human body releases sweat vapour. Only when this vapour meets a temperature greatly different from the one it was created in does it condense into liquid or ice. Because vapour molecules are many times smaller than droplets of water, your sweat is able to pass through the microscopic pores in the skin of the waterproof fabric. At the same time, raindrops continue to be repelled by the material.

Some other breathable fabrics work by allowing sweat vapour to travel along individual fibres from one side of the fabric to the other. Of course, individual manufacturers of waterproof-breathable materials all have their own way of describing how their fabrics work and why they are superior to all others on the market.

Despite some manufacturers’ claims to the contrary, all outdoor clothing adheres to the principle of ‘layering’. Traditionally, layering systems have been described as a three-stage concept, although as we’ll see later there are many exceptions to this rule. But three layers is as good a place as any to start.

Working inside out, the first layer – known as the ‘base layer’ – is worn next to the skin. The function of the base layer is twofold. Firstly, it draws sweat vapour away from the skin, leaving you feeling dry. (If the skin is left feeling damp from condensed sweat then the body can chill rapidly once activity ceases and the body starts to cool down.) The other function of the base layer is to push this sweat vapour into the next layer of clothing. Generally speaking, base layers are not designed to retain more than a semblance of body heat, which is why these garments tend to be quite thin.

The ‘mid layer’ is worn over the base layer. Unlike the base layer, the mid layer’s primary role is heat conservation. Its secondary role is to allow the sweat vapour picked up by the base layer to continue on its journey away from the skin. The number and thickness of mid layer fabrics you decide to wear will be dictated by the ambient temperature and type of activity you are engaged in. Most people find that two thinner mid layers are warmer and more versatile than one thick garment.

It is also worth bearing in mind that when you are working hard, even in sub-zero conditions, the amount of heat the body generates can be so high that sometimes there is no need to wear any sort of mid layer whilst exercising. In these circumstances, it is important to keep a mid layer or two stowed in the rucksack ready to be donned when you take a break.

The third component of the traditional layering system is the ‘outer layer.’ A modern outer layer must perform two important tasks. Firstly, it needs to prevent the elements from infiltrating the other layers of clothing. Wind, rain, hail and snow may all need to be deflected. Secondly, the outer layer needs to allow as much of that sweat vapour as possible to escape.

By resisting wind and precipitation, and by allowing sweat to pass through the fabric, a high performance outer layer will go a long way to keeping base and mid layer(s) dry. And dry clothing is so much better at insulating you than wet garments.

staying dry from within
Regardless of the brand of waterproof-breathable fabric that you buy into, one thing is for sure: if you wear absorbent materials under the outer layer, the breathable quality of the material will be rendered useless by virtue of the fact that the sweat vapour will become trapped within the fibres of the inner and mid layers before it has a chance to reach the outer layer.

All of which means that cotton (and to a lesser degree, silk) are non-starters in cold and wet weather layering systems. Cotton soaks up moisture like a sponge; that’s great in a bath towel, but a positive liability in damp and chilly weather.Wearing cotton in these situations is more often than not a short cut to hypothermia, a life-threatening medical condition. By contrast, specially treated polyester fabrics (including fibre-pile and fleece), and certain natural materials – such as Merino wool – are superb at allowing sweat vapour to pass through their fibres.

It is worth noting that outer layers which are windproof but not waterproof will almost always enjoy a higher level of breathability than fully waterproof-breathable products. This makes windproof-only garments very suitable for dry cold or showery conditions as they allow sweat vapour to escape even more quickly. The benefits of this increased breathability are exploited in so-called ‘soft shell’ products.

duvet jackets
the soft shell alternative
Sometimes, any sort of layering system simply isn’t warm enough. After all, there is a limit to the number of layers that it is possible to wear before normal movement becomes severely constricted. So in deep cold conditions, or in chilly weather where you are likely to remain static for any length of time, a heavily insulated garment – known as a duvet jacket – is useful. Duvet jackets are normally too warm to be worn whilst active, except in situations such as high-altitude mountaineering. More usually, they are worn during rest breaks. Lighterweight, pullover-style versions are also available. These are perfect for wearing in less extreme conditions, and are a warmer and lighter alternative to a spare mid-layer.

Duvet jackets are phenomenally effective at trapping body heat. I find they are most effective when worn as close to the skin as possible. For that reason, I normally prefer to wear just a single dry base layer under my duvet. Of course sometimes this is not practical and the duvet simply has to be worn on top of all the other layers.

Duvets are made from the type of down or synthetic filling used in sleeping bags, rather than pile or fleece fabrics.

As we have already seen, the current crop of guaranteed waterproof garments cannot allow as much sweat vapour to escape as non-waterproof, windproof shells. So in situations where rain is less likely (for example, trekking to Everest in the pre- or post-monsoon seasons) or in places where any moisture is likely to fall as dry powder (such as Scandinavia in the winter months) then a highly breathable soft shell makes a lot of sense.

Originally seen in a fabric developed for the Royal Air Force in the Second World War, the modern concept of soft shells owes its origins to Hamish Hamilton, whose range of Buffalo clothing has inspired many imitators. Hamilton originally designed his clothing to be used in the invariably damp pursuit of Scottish winter mountaineering. In contrast to the traditional three layer system described earlier, Hamilton’s garments – which consisted of a warm and fast-wicking fibre-pile with an integral windproof and highly water-resistant nylon outer – were (and are) designed to be worn next to the skin, with no base layer. Cleverly-placed zips allow the user to periodically vent the clothing, allowing cool air to rush in and quickly dry the skin. Even when soaked, Buffalo clothing continues to work efficiently, trapping heat and pushing water away from the body. Field-maintainable, easily repairable and relatively inexpensive, many of Buffalo’s concepts have now been taken up by rival manufacturers.

Yet soft shell clothing does not completely eschew the layering system. Buffalo makes additional garments that can be worn over its shirts for situations such as when the climber is loitering on belay stances and likely to cool down rapidly. Other manufacturers have produced soft shell outer layers that are simply worn on top of existing, conventional base and mid layers.

The bottom line when deciding whether to opt for a traditional ‘hard’ waterproof-breathable jacket, or an arguably more flexible ‘soft’ shell, is to examine closely the type of activity you engage in. If most of the time you expect to be in situations where heavy rain is not only possible but likely, then a hard shell will be essential from a safety point-of-view. Hard shells are also pretty much de rigeur on camping expeditions in temperate climates, where keeping clothes as dry as possible for days or weeks at a time is important. If, on the other hand, rain is unlikely and even if it does rain then shelter or an umbrella is to hand (or is irrelevant as you’ll be working so hard as to generate sufficient heat to keep warm whilst wet), a soft shell jacket could be an interesting and more comfortable alternative worthy of further investigation. Inevitably, many outdoor users end up owning one of each, in order to give themselves the greatest choice depending on what the weather is doing on any given day.

protecting extremities
Your head, face and hands require special attention in cold and wet weather. This is especially true in low temperatures, when fingers, noses and ears can become particularly susceptible to frostbite.

Given that a large percentage of body heat is lost through the skull, wearing a wool or fleece hat is a quick way to raise your temperature; it’s a bit like putting a lid on a pan of boiling water. Balaclavas help to insulate cheeks and chins. In extremely low temperatures, a neoprene face mask is more effective than a fabric balaclava since it remains flexible in sub-zero conditions.

Fingers can be difficult to keep warm, especially when a high level of dexterity is required. Mittens tend to be warmer than gloves, as fingers can share warmth in a mitten. Some mittens have a flap at the base of the fingers to allow digits to be exposed as and when required. Other mittens have a so-called ‘trigger finger’ which allows the forefinger to be used separately alongside the thumb. This is useful if you want to take photos. Thin base layer gloves can be worn under mittens if required.

In less extreme conditions, windproof fleece gloves often suffice. Finally, separate wristlets help to maintain bloodflow through the wrists and hands.

keeping feet warm
garment features
Contrary to popular belief, it is sometimes necessary to wear thinner socks in order to keep feet warm in cold weather! This is because a foot squeezed into tight-fitting footwear is difficult to wriggle around. Such cramping can lead to a sluggishness in blood flow. Of course, it is much better to buy slightly looser-fitting footwear that allows thick socks to be worn comfortably.

High altitude and dehydration also play a part in making feet cold. Unlike face and hands (which can be checked easily for signs of frost damage), feet tend to spend all day out of sight, which increases the chance of minor frost damage developing into something more serious if left unchecked. Feet that are cold in the morning are likely to be cold all day, so do what you can to warm up your footwear before the start of the morning. Some campers sleep with their boots in the bottom of their sleeping bags.

High altitude mountaineers wear footwear with integral overboots and removable liners which make them easy to warm up prior to putting on. For cold-weather walkers, a heavily padded soft boot with a special rubber sole – that is particularly sticky in sub-zero icy conditions – provides a much higher degree of warmth and traction than a conventional trekking boot.

Thinking about what you want your clothing to do will help you to decide which features are worth paying for, and which ones are superfluous to your needs. After all, it is easy to get carried away with all sorts of zips, pockets, cords, and other assorted ‘bells and whistles’, leaving you with unnecessarily over-engineered – and heavy – apparel.

If you are intending to purchase a waterproof outer layer, then seams that have been sealed on the inside of the garment with tape are essential. Otherwise rain will be able to penetrate through the stitch holes. By contrast, the majority of soft shell and windproof garments do not have expensive taped seams, as the fabric itself isn’t waterproof.

Some fleece mid-layers are also windproof. These can be wonderful in essentially dry and cold conditions, but in perpetually damp weather you are likely to be wearing some sort of separate outer layer, making the additional benefits of windproof fleece largely redundant.

In addition to the venting characteristics of certain soft shell garments described earlier, some technical mid and outer layers sport underarm ‘pit zips’ which allows unwanted heat (and sweat) to escape. These are particularly useful in wet weather when it is not ideal to have to undo the front zip.

Despite the great lengths that manufacturers have gone to with advances such as reverse-coil zips, in sustained wet weather the contents of your outer layer pockets are likely to become damp. Furthermore, pockets located low down on jackets are likely to be covered up by a rucksack hip belt or a climbing harness. So if you are a mountaineer, a small number of chest-mounted pockets might make more sense.

Take the time to try on each garment properly. Don’t forget to pull on the hood, which is arguably the most important feature on an outer jacket.

On the subject of legwear, the question of side zips comes to the fore. Full-length zips are more expensive, heavier and potentially less waterproof than trousers that have half-length zips. But full-length zips allow easy donning/doffing over snowshoes, skis and crampons. Winter activists will also have to choose between trousers and salopettes. Trousers are cheaper, quicker to pull on, and more versatile over a wider temperature range. Salopettes are warmer, since they trap heat around the small of the back and across the chest. Braces help to keep salopettes in position throughout the day.

All outdoor activities are potentially hazardous. The information provided on this site offers guidelines only, and is no substitute for personal instruction from a qualified person. Whilst every effort has been made to ensure the accuracy of the information, no responsibility can be accepted by the author or Cotswold Outdoor Ltd. for any errors or omissions. By choosing to follow any of the advice contained in this leaflet, the reader accepts personal responsibility for a) learning any techniques required, b) any risks involved, and c) any damages or injuries of any kind - including death - howsoever caused. Cover shot: Checking the way ahead on the Trekker's Haute Route, between Chamonix and Zermatt.
© Paul Deegan & Flirt Design under license to Cotswold Outdoor Ltd.