One of the main problems faced when practicing mountain activities is the proper clothing. During an excursion or a simple walk in the mountains, temperatures can be very variable both for the weather and for the intensity of physics that takes place. There is a risk of wearing clothes that are sometimes too hot, others excessively light .
When you do outdoor activities, therefore, layered clothing becomes the smartest way to manage thermoregulation.
This strategy allows you to perfectly adjust the comfort of your body, adding or removing clothing according to the level of physical activity or according to changes in climatic conditions.
In colloquial jargon the expression is used: “to dress like an onion” . Just like the onion, in fact, several removable layers are worn if necessary.
To better understand the importance of layering clothes for outdoor activities, it is necessary to know the functions of each layer (or layer, in fact):
- Inner layer (functional underwear layer): wicks sweat away from the skin
- Middle layer (insulation layer): retains body heat to protect you from the cold
- Outer layer (protective layer or shell): protects you from wind and rain
Even if you don’t wear all three layers of protection when you go on a hike, snowshoe walk or ski session, it’s still a good idea to bring all your clothing with you to recompose the layers as needed; otherwise you could just take something off if the temperature were to rise, but you couldn’t add layers without having them with you.
Now let’s see more specifically what are the functions and materials that make up each layer.
Inner or base layer: useful in moisture management
As a layer next to the skin, the function of the inner layer is essentially to remove sweat from the skin, or to “absorb” excess sweat so as not to leave the skin damp .
In cold weather, base layers of long underwear are needed to keep the skin warm as well as dry. This precaution is essential because it avoids, in the most extreme cases, the risk of hypothermia .
What are the best materials for the inner layer
There is a wide range of fabric options, including technical fabrics like polyester and nylon or natural fibers like merino wool and silk.
Although the differences are subtle in both the breathability and drying of each material, and the retention and durability of odors, many people simply choose their personal preference for the fabric.
Weight of the garments that make up the inner layer
In this case the alternatives are very simple: light weight, sometimes it is possible to run into “ultralight”, medium and heavy weight variants.
Generally heavier (thicker) fabrics keep you warmer, although, as we have already said, the main purpose of an inner layer is not related to thermoregulation but to the absorption of sweat.
Base layers suitable for hot weather
A particular clarification should be made on underwear in case of particularly favorable climatic conditions. In fact, although long underwear may not seem ideal when temperatures rise, having dry skin generally allows you to have greater comfort in all conditions .
Let’s now make some other useful considerations on the inner layer to wear when temperatures are hot:
- Any summer shirt could be considered a “base layer,” so look for the ones that offer the most absorption. How to find out? First, take a look at the construction materials and the technical data sheet.
- Some shirts designed for the hot season disperse moisture through the fabric which, thanks to evaporation, helps cool the body. These garments are technically not considered an inner layer, but as a layer close to the skin they can increase comfort in hot conditions.
- Underwear such as briefs , boxers and bras should also help absorb moisture. This aspect is also important when they are worn under long underwear in winter.
- UPF-rated inner layers offer added sun protection.
- The cotton , perfect on a hot and dry day, it is rather useless in the winter because it holds a lot of water, because of cold temperatures can freeze and cool the body.
- The latest technologies in the field of fabrics, such as wool mixed with ceramic particles , create excellent garments for the inner layers, which can literally cool the skin for greater comfort.
The intermediate layer performs the function of insulation
The insulating layer, also called the intermediate layer, helps you to keep the heat radiated from your body . The more efficiently this layer traps that heat, the more you will experience a pleasantly warm sensation.
What are the best materials for the middle layer
Just like we saw with the inner layers, you also have a wide range of options for the middle layer, both synthetic and natural.
Generally we start from the assumption that thicker (or more swollen) is synonymous with warmer, but we must not neglect the efficiency of the insulating material , at least as important as the thickness of the garment.
Let’s see some fairly common materials in the middle layers:
- Polyester fleece
Available in light, medium and heavy fabrics; sometimes marketed by weight (100, 200 and 300 grams). Polyester has the advantage of retaining heat even when wet, and it dries quickly. Sweatshirts breathe well, so they are less likely to overheat inside.
- Fleece sweatshirts for men and women
If great breathability is an important advantage, it is also right to underline that the same feature favors the passage of wind through the fabric, and this can mean heat dispersion. That is why it is essential to have an outer layer (the so-called shell) as well when you wear a fleece mid-layer.
Alternatively, you can replace the shell with a windproof one, equipped with an internal membrane that blocks the passage of air.
Sports jackets for men and sports jackets for women
- Down insulating jackets
Easy to compress and, consequently, to carry, down, in relation to its weight, offers more warmth than any other insulating material. The efficiency of the down is measured in fill power , which varies between 450 and 900.
Since the down is always inside a shell material, the down jackets also offer a certain resistance to water and wind. The disadvantage is that this clothing loses its insulating efficiency when wet.
- Synthetic (technical) insulating jackets : paddings, or synthetic insulators, have been created for some time to try to reproduce the efficiency of down; we must say that year after year they are getting closer and closer to the standard one.
Although synthetic materials don’t compress as well as down, they are a very popular option for rainy conditions because they preserve the insulating capacity when they get wet. As with down, in fact, the synthetic insulation is always inside a shell material that offers greater resistance to water and wind.
Outer layer: ideal as protection from rain and wind
The outer layer (protective layer or shell) protects you from wind, rain and snow . The shells range from mountaineering jackets, which are much more expensive, to simpler, but still wind-resistant jackets.
Most of these garments let at least some sweat transpire. Plus all should be treated with a durable water repellent ( DWR ) finish .
The outer shell is essential in extreme cases, such as a storm , where if wind and water penetrate you could seriously risk freezing.
The shells can be grouped into the following main categories:
- Waterproof / Breathable Shells : The most functional (and expensive) choice, this type of shell is the best option for extreme conditions. In general, in the context of mountain clothing, more expensive equals drier; moreover, the more expensive shells are often more durable.
- Water Resistant / Breathable Shells : They are best suited to drizzly, airy conditions and high levels of physical activity. More affordable than waterproof / breathable shells, they are typically made from tightly woven nylon or polyester fabrics, which block light wind and light rain.
- Soft shell shells : emphasize breathability. Most feature stretch or full stretch fabric panels for added comfort during aerobic activities. Many combine light rain resistance and wind protection with light insulation, then combine two layers into one jacket.
- Waterproof / Non Breathable Shells : These shells are suitable for rainy days, without activities (e.g. fishing, recreational events in the mountains). They are typically made of coated nylon, which is water and wind resistant. If you engage in activities while wearing one, you will likely end up soaking your underlying layers with sweat.
Examples of layered clothing for the mountains, in case of cold, rain and heat
Given the importance of wearing layered clothing, we often ask ourselves how to dress for the mountains in winter and summer , or in case of different weather conditions.
Any suggestions based solely on climate, however, overlook key considerations, such as exertion level and personal metabolism.
The following examples are built on a hypothetical person who does not suffer particularly hot or cold, who is doing a half-day hike of intermediate difficulty.
Dress in layers for cold environments
- upper and lower part of the underwear in medium-light polyester;
- a jacket with synthetic insulation;
- medium weight brushed trousers;
- waterproof / breathable rain jacket and trousers.
Dress in layers for humid and rainy environments with normal temperatures
- long underwear, in light polyester, both for the upper part and for the legs;
- light fleece jacket;
- technical trekking pants;
- Lightweight and breathable waterproof jacket and pants (with many vents).
Dress in layers for warm environments
- polyester briefs and short-sleeved synthetic T-shirt;
- convertible nylon trekking pants;
- light windbreaker.
Those listed are obviously only examples, in fact there are multiple alternatives, all valid and extremely functional for each of the hypothesized situations. The trick, trivially, is to choose the ideal solutions in relation to your destination, the time of the year in which you move, the sport you have to practice, the budget and, why not, your aesthetic preferences.
Once the choice has been made and the garments purchased, it is equally important to find the right feeling with them, to manage them in the best possible way in any eventuality, according to contingent needs. For example, if the rain and wind stop, remove the shell; if the physical activity is not intense enough to generate enough heat, add an intermediate layer… .and so on!
Many people prefer to wear an additional mid-layer and / or outer layer at each stop, just to avoid the feeling of cold and the possible consequences of a sweat. Ultimately we can say that the choice of technical mountain clothing is undoubtedly subjective, but at the same time it should be done in a thoughtful and conscious way.