Spending time in the outdoors you will always encounter a variety of weather and temperatures, regardless of the activity. You might be bush-walking, rock-climbing, adventure-racing, ice climbing or simply travelling – but the chances are you’ll encounter some variable weather. The best protection against these forces of nature is your clothing. Insulating you from the cold, shielding you from the sun, creating a barrier from the wind, and keeping you dry when it’s wet. Choosing which clothing to wear or pack will depend on both the expected (or unexpected!) weather conditions and the activity you’re undertaking. In regions where harsh weather is present, having the appropriate clothing can be the difference between suffering miserably and having a great trip regardless of the forecast. Likewise, if you’re caught out wearing the wrong clothing (or none at all…) it can lead to any number of problems, such as hypothermia, sunstroke or worse. Here in Australia the conditions you may encounter can be quite extreme, from -15°C blizzards in the Australian Alps, to blistering heatwaves exceeding 40°C. OK, so have we got your attention? Basically, the clothing you wear the outdoors is important. With that in mind, we’ve put together a guide to what is known as the ‘layering system’. What it boils down to is that appreciating some basic principles (coupled with your own experience and that of your peers) will have you spending more time enjoying the outdoors, rather than enduring it. This article draws on both proven and time-tested knowledge, plus some of my personal experiences and preferences on this topic. The layering principle From speaking to customers and less outdoorsy friends, it is quite apparent that technical clothing and layering can be a mystery to many. In reality, layering is a surprisingly simple and well proven principle for dressing in the outdoors. Fundamentally, you wear a larger number of light layers of clothing rather than fewer thick bulky layers. This has several great benefits. The most advantageous for me, is the versatility. You can tailor your layers to suit any climate, weather and activity. Likewise whilst you are out there enjoying the outdoors you can add or remove layers as necessary, responding to changes in the conditions or the activity. Then there’s warmth. For cold conditions, air is trapped between & inside these layers creating a higher level of insulation. There are a numerous other factors to consider, such as weight, durability and even style. Before we get too bogged down in all that let’s establish what these layers are. Most clothing can be grouped into 4 basic categories: Base Layer, Mid Layer, Insulation Layer & Outer Layer. Of course there are exceptions to this rule and a lot of clothing will fit into several of these categories. Firstly, we’ll focus on the upper body layers, but keep in mind much of this information is also relevant for the legs. The picture below illustrates a typical cool-to-cold weather layering system. Pictured: Base – Icebreaker Oasis Crew. Mid – Arc’teryx Covert Cardigan. Insulation – Patagonia Down Sweater. Outer – Arc’teryx Theta AR GTX 1. Base Layers Considered by many as the most important layer, the base layer is what you wear right against your skin. In many cases this is the layer you put on in the morning and take off at the end of the day. Or for those who prefer longer adventures, you’ll put on at the beginning of a trip and peel it off 2 weeks later… yes that happens. Thoughts on personal hygiene aside, why is a base layer so key you ask? Well it performs the very important task of keeping you comfortable by wicking the sweat from your skin, then dispersing it to the next layer where it can eventually evaporate. Water is an excellent heat conductor, so a wet next-to-skin garment can draw vital heat away from your skin as much as 20 times faster than a dry one. Don’t be fooled into thinking this is only an issue when in cold conditions either. Even in above-freezing conditions, rapid heat loss can trigger a dangerous drop in your body’s core temperature, potentially leading to hypothermia. So are you convinced that good base layers are important yet? The fabric your base layer is constructed from is also really important. In a nut shell, either Merino Wool or Synthetic based garments are your friend. Icebreaker merino wool is a personal favourite, it’s soft, regulates temperature well, is highly durable and remarkably stink-free due to do Merino’s antibacterial properties. Polypropylene is another common base layer material and also quite cost-effective, the 360 Degrees base layers offer value for money. Just don’t expect your poly-pro garments to remain sweet smelling for long. Higher end synthetic base layers from Helly Hansen offer a better fit, anti microbial treatments such as Polygene and are a great alternatives to merino. For gram counters, synthetic base layers will be comparably lighter warmth-to-weight than merino but you might need to pack more, or just suck it up and wear stinky layers. Base layers will come in a variety of weights to meet the demands of different activities. A light-weight layer would be suitable for milder conditions or for activities with temperature fluctuations. Comparatively heavy-weight base layers are suitable for very cold conditions or cold, low-output activities (such as snow camping). For most people, a mid-weight or standard-weight base layer is a good place to start and offers the best versatility. In Icebreaker terms, look for ratings such as 150, 200 and 260 weight. A base layer should fit snugly but not be restricting, these are not compression garments. Finally, consider style, this isn’t solely underwear, you will often find yourself hiking, climbing, skiing or sitting around in your base-layer, it’s gotta look good too! My pick: Personally I can’t go past a time-tested Icebreaker Oasis 200 weight . I’ve been using my original Oasis tops and bottoms for years & despite owning a variety of other base layers, these get the most use by far. 2. Mid Layers Next up is a mid-layer. This a fairly ambiguous term, but basically for the purpose of our layering system, it’s something you wear over your base layer when the condition’s call for a bit of extra warmth. Usually this will be in the form of a Men’s or Women’s fleece, such as a 100 weight or 200 weight in traditional terms, or a men’s or women’s Merino mid layer equivalent. Generally you will want your mid layer to feature a zipper, be it half-length or full-length. A half zip will be less bulky, but a full zip offers more venting options. Which you choose will boil down to personal preference and the activities you’re buying it for. Mid layer items are also often worn alone (over your base-layer) on shorter trips and in mild weather conditions. The pieces you choose should be comfortable, lightweight and more robust than your base layer clothing. For me, a lightweight fleece with a half or full zip works for most activities. I heat up rapidly when working hard, so in dry/cool conditions I’ll often be found just wearing a base-layer under 100 weight fleece. 3. Insulation Layers In cold conditions, this layer will have you smiling and just loving life. An insulation layer garment is designed specifically to provide additional warmth. It’s typically worn whenever a mid layer and/or inner layer pieces are not warm enough for the current conditions. The insulation layers you use should be warm, lightweight and as low-bulk (or compressible) as possible. They should also breathe well to allow sweat and body heat escape, thus regulating your core body temperature. To slow heat loss, this layer must be capable of retaining the warmth that is generated by your body. In cool-cold conditions, synthetics and wool are well suited for this purpose because the structure of the fibres creates small air spaces that trap molecules of warm air. Full length front zippers, or areas of lesser insulation are designed to allow venting. Here are a selection on Men’s and Women’s insulated jackets and vests. Going somewhere really cold? By far the king of insulation is still down. Synthetic fill garments are rapidly catching up, but for now nothing can compete with down’s ability to loft (puff up), offering incredible amounts of warmth for very little weight and bulk. Of course all down isn’t created equal and neither are all down jackets. A lighter high-loft and highly compressible down jacket will be great for most conditions, whilst a big jumbo puffer will be your saving grace in extreme conditions. As far as moisture management goes, synthetics absorb little water, allowing faster evaporation. Synthetic based insulted layers (jackets and vests) are not only lightweight, they are also very durable. When down gets wet it loses its insulating properties, whilst synthetics retain almost all of their thermal efficiency when wet. If you’re going somewhere that’s likely to be very wet, consider a synthetic option. Insulation is a big topic; if you want to learn more, check out our guide to choosing a down or synthetic insulated jacket. Geoff loving some cold morning temps wrapped in the super-warm Rab Neutrino Endurance Down Parka. 4. Outer Layers The primary job of the outer layer (or shell) clothing is to protect you from the wind, rain, and snow. But it needs to be somewhat breathable as well, to let sweat and body heat escape. If you’re not sure weather to take your outer layer into the outdoors, the answer is almost always yes. Nothing will save you from unexpected changing in weather like a good outer layer jacket. Whether you’re stuck in sudden storms, faced with drastic drops in temperature, or cresting a ridge to find yourself in high winds, your outer layer will come to the rescue. Here are a selection on Men’s and Women’s outer layer waterproof jackets. For dry conditions, a breathable (non-membrane based) wind shell may be all you need. For most people, especially given our wet climate here in Australia, a waterproof-breathable jacket will be more versatile. This garment will be a full-zip hooded jacket, that is constructed using breathable membrane fabrics such as Gore-Tex, eVent. This shell layer will give you protection from wind and rain, as well as allowing water vapour to escape. For a more detailed look at outer layer shell jackets and some tips on selecting the best one for you, check out our Choosing A Waterproof Jacket article. Keep in mind there are no miracle fabrics. During vigorous activity, your body simply produces more water vapour than any fabric can disperse. The result can be a build-up of moisture on the inside of the garment, leaving you wet, clammy and cold. Whenever possible, strip off a layer or open any ventilation zippers before this happens. Outer layers are critical in extreme conditions, such as this winter trip snow-shoeing up Mount Bogong in a Blizzard. Pictured: The below illustration demonstrates another take on a 4-layer set-up, featuring some women’s garments. The base layer is a 200 weight Icebreaker Oasis with a half zip and hood. The mid layer is the Rab Flux, which sits somewhere between a base-layer and mid layer, but could be used as either/both. The Arc’teryx Atom Lt hooded insulation layer is a lightweight Synthetic insulation piece, again with a hood. Hoods are a personal preference thing, but they do offer essential head insulation for minimal extra bulk and weight. The Outer Layer is the Rab Muztag Jacket, which uses a super lightweight and highly breathable 3-Layer eVent membrane. A setup like this would be ideal for someone undertaking high-output activities, such as ultra-light hiking or summer alpine climbing, where saving on space and weight can be critical. Pants: Leg Layers “But what about my legs?” you must be asking. Well most of what you’ve just read about the upper body applies for the legs, with a few variations. First of all, your legs don’t house any vital organs, so they’re less important and less likely to feel the cold. That said, you’ll still need to think about layers for your legs. The base layer is going to be the same, a long pair of Merino or Synthetic underwear. Keep in mind that you may not need to wear this under-layer all the time, and if worn whilst engaged in a high output activity, you’ll probably only wear them in really cold conditions. Don’t forget to pack your leg base-layer though, as you’ll want them, for example when you you’re not moving and the temperatures plummet overnight. A lot of hikers will only put on their ‘long-johns’ at the end of the day, when they’re reached camp for the night, they also make great sleep attire. Your most common leg layer will be a good pair of trekking pants, lightweight, quick drying and made from predominantly a polyester or nylon blended fabric. These come in many different styles, ranging from super lightweight, to heavier Men’s and Women’s soft-shell pants that will be warmer and block a lot of wind. The outer leg layer is your shell (see Men’s and Women’s waterproof shell pants). These offer protection for the weather like your outer layer jacket. Look for breathable fabrics as proven as a preference for most people, zippers that extend above the knee to allow getting the pants on/off over boots. Head insulation Now that the body is sorted, let’s look at your noggin. It’s estimated that up to fifty percent of a person’s total heat loss can occur through the head. Subsequently, your head acts like a radiator, allowing heat to escape. This can put unnecessary strain on the rest of your system because your body must now use additional energy to reheat the blood as it circulates. A good Beanie or Balaclava will not only slow heat loss through your head, it will also make your hands and feet feel warmer because of the improved circulation. As with base and mid layers, look for beanies made from Merino wool, fleece or polypropylene. In extremely cold conditions, nothing protects your face or keeps in heat like a full-face balaclava, just don’t wear it into the local bank… Then there are neck warming duties. A personal favourite is a thinner neck chute, such as those made by Buff or Icebreaker. These can often be worn in any number of combinations including the following components: neck warmer, beanie/hat, balaclava, headband, etc. Hand and Feet Insulation In its effort to keep your head and your body’s vital organs warm in cold conditions, the heart reduces blood flow to the extremities (hands and feet). These areas do not generate much heat on their own, so some insulation and protection from the elements is needed. For example, mittens are warmer than an equivalent pair of gloves because the whole hand contributes to the warming process, however mitts inhibit dexterity. Gloves are better for activities that require greater freedom of movement, such as tying knots, but because each finger must warm up its own little compartment, it makes them less efficient in the game of keeping your hands warm. A layering system that consists of a thin synthetic or merino wool glove for moisture transport, an insulating mitten and a non-insulated shell mitten for outer protection will give you a wide range of temperature control, if you require more manual dexterity try using a lined glove shell. Check out glove options here. Keeping your feet warm and dry is absolutely imperative on outdoor adventures. Your choice of socks can make or break a trip, if your feet are suffering it’s hard to enjoy anything. Synthetic, Merino wool, Tencil (eucalyptus fibre) – or a blend of several of these – is the preferred material. These materials provide the optimum balance of moisture management, warmth, durability, and cushioning. The addition of a liner sock will add warmth and speed up moisture transport from the feet to the outer layer. Weather you use a liner sock is personal preference, but if you do use one keep in mind your main so might need to be thinner to accommodate the extra bulk. Socks should fit snugly. If they’re too tight, circulation can be restricted and your feet will get cold. Conversely, a loose sock can slip or move around, creating pressure spots that can lead to blisters. If blisters are something you grapple with, or something you want to avoid (everyone does), have a read of our foot care & blister tips article. Sizing & Fit This one is important. When building a layering system, consider sizing and fit. If possible, try on your layers in sequence when purchasing them, even if that means bringing your existing garments to the store. You’ll need to consider a few things, comfort, freedom of movement, arm articulation, sleeve length, hem length/over-lap, hood coverage, etc. It’s also never advisable to get your insulation layer too snug, or cover it with a layer that compresses the insulation. Both cases will reduce the potential warmth of that garment. Likewise don’t buy your layers too big, they will lose some thermal efficiency and just will not be comfortable to wear. Another factor to consider is how well the layers ‘interact’, by that I mean do the fabrics get caught on each other and cause discomfort? Or do they slide across each other moving somewhat independently? Also, keep an eye out for bulky stitched seams that will line up with each other and might rub under your pack’s harness. Personally, I can’t tolerate a base layer and mid layer that cling together pulling in all sorts of annoying directions. There are the rules, now break them. This isn’t a regimented system that you MUST follow to the letter. Think of it as a a place to start, a guideline. My hope is that in time you will create a personalised layering system for your specific requirement and preferences. It might take a lifetime, but be warned, layers are addictive! Here’s a few extraneous thoughts on mixing things up. In some cases exchanging your mid layer with a wind proof/resistant layer could be beneficial. Generally this would be in the case of a soft-shell jacket of some kind. If you’re engaged in a high-output activity with a high likelihood of wind-chill, consider this. For example, an outer layer may not be breathable enough, whilst your insulation layer will be too warm. If you’re in really cold/dry environments, snow camping, winter ice climbing, high altitude mountaineering or polar dog sledding… the outer layer might in fact be an additional insulation layer that is worn over your hard-shell layer. This is known as your expedition parka for climbers, a belay jacket. I could go on… but this article is already wordy enough, let’s leave some of the fun for future laying explorations. Happy Layering! Nothing can ruin an outdoor activity quicker than being cold and miserable. Whether you’re shivering cold and wet, or overheating and wet from your own sweat, it’s not fun and can impact your experience both mentally and physically. A guide in New Zealand, who has spend more days in the mountains , gave me the best answer to that tough question: how many layers should I be wearing right now? His advice, which I’ve taken on board ever since, was that you should aim to be comfortably cool when engaged in activity. This allows your body to be functioning efficiently and not over working to regulate your core temperature. Once you’re stationary, then try to aim to be comfortably warm. I’ve found it’s better to be a bit cool before setting off on a long bout of hiking, than to be already overheating and peeling off layers constantly. Take the time to considering what layers you’re wearing and packing. It will not only enhance your enjoyment in the outdoors, but you’ll look swish too! Just think of layering as the relatively simple concept of dressing in a way that allows you to adjust to a wide range of conditions. Hopefully this has cleared up some of that ‘layering mystery’. If you have any further queries feel free to leave a comment below. Scotty layering up with his Patagonia Nano Air Hoody, just as the sun disappears leaving us in the cold valley below The Nun’s Viel, Aoraki/Mount Cook National Park, NZ. One Response Adam Axford November 6, 2019 Great article. This is really informative for people who are planning for an adventure trip in the mountains for the first time. they really don’t have an exact idea what to carry from the closet. Thanks for sharing this informative post. Reply Leave a Reply Cancel Reply Your email address will not be published.CommentName* Email* Website Notify me of follow-up comments by email. Notify me of new posts by email.