How To/Advice / Mountaineering / Outdoor / Walking /
THE LAYERING SYSTEM - IT’S ALL ABOUT COMFORT
When we’re out in the hills, forests and mountains, part of the excitement and challenge that comes with it are the rapidly changing weather conditions and levels of physical exertion. This produces many different variables for our bodies to cope with. However, by adapting your base, mid and outer layer you can survive, even stay comfortable, in almost any conditions.
For example, if you’re starting at the foot of Snowdon in the height of summer, you wouldn’t wear the same number of layers you’d pile on in winter as you’d be heaving with sweat 100 metres in. But if you’ve got layering options with you, you’ll be able to cope as the temperature dips, as you you gain height and as the weather conditions change, should you need to to batten down the hatches to reach the summit (hopefully still smiling with tales of adventure to tell).
Unfortunately there’s no set formula for a perfect outdoor clothing set up, however the layering system enables us to master nearly any environment giving us the versatility to go anywhere we choose. In this article we will explain how layers can work both independently and together to keep you in comfort whatever the activity or weather condition.
The Base Layer (Moisture Management) Back To Top
As the name suggests, this layer is worn next to the skin. It’s main purpose is to regulate your body temperature. A good base layer works to aid your body’s natural processes, like sweating, to have maximum effect.
If sweat is held trapped against the skin as soon as your level of physical exertion drops you will quickly become cold. That’s why cotton is best avoided for outdoor activities as it holds on to moisture and doesn’t move/wick it away from the skin.
Synthetic materials like Polyester and Polypropylene are excellent at moving moisture away from the skin, helping it to evaporate. For high energy activities, like running, quick drying materials are perfect and function well in hot and cold conditions.
However wool has properties that make it highly effective across a range of temperatures and a popular choice for activities, such as, hiking and skiing. Merino wool, in particular, is non-itchy, wicks well, has insulating properties and doesn’t hold on to body odour like synthetics.
The Mid Layer (Insulating Layer) Back To Top
Often called the insulation layer, this is where your warmth comes from. Common examples of mid layers include fleece, down and synthetic insulation. There are a number of different types of mid layer but they all aim to trap your body heat, whilst remaining breathable should your activity rate pick up, and you need to cool down.
Fleeces come in different thicknesses and provide affordable, quick drying and breathable warmth. As with the base layer, thicker merino wool can work well and is a luxurious option in colder environments. Similarly down, which is an excellent insulator with a brilliant warmth to weight ratio, can be highly effective in extreme cold and dry conditions or for low intensity activities.
Again, it’s best to avoid cotton mid layers (such as your favourite hoody) as they will retain moisture which can lead to you getting cold. There are numerous types of insulation and they don’t need to be particularly technical – the humble fleece is perfect for most activities. The important factor is to choose the right level of warmth to suit your activity and weather conditions.
In milder conditions a mid layer could also be your outer layer but when the weather closes in you’ll need a dedicated layer or shell to be worn on top of your insulation.
The Outer Layer (Protection From The Elements) Back To Top
This layer is your first and last defence against the elements. This is what protects you from the rushing wind, the lashing rain and the howling blizzard and enables your base layer and mid layer to effectively wick away sweat and keep you warm . A good outer layer or shell, whilst stopping the elements from coming in, will also allow the moisture and heat from your body escape to so you don’t overheat.
The classic outer layer that will defend against the most adverse of conditions is the waterproof hard shell. There’s a wide range of waterproofs available but for best performance and true waterproof protection, it must have taped seams, suitable weather protection zips and offer a good level of breathability. Top performing examples of these use Gore-Tex or Event membranes for maximum reliability and durability. Depending on your activity and the conditions water repellent coatings (known as DWR – durable water repellent) can also provide a good level of waterproofing and breathability and often work well as a light outer layer.
Depending on weather conditions, the outer layer does not necessarily need to be fully waterproof. Soft Shell jackets offer excellent comfort as they are stretchy and flexible, provide good wind resistance and are more breathable than even the best waterproofs. The soft shell can also work as an excellent mid layer in cooler weather conditions when combined with a waterproof shell.
In very cold conditions an insulated, synthetic or down jacket can be highly effective as the outer layer but it is important to have further layering options if activity levels or weather conditions fluctuate considerably.
When To Use These Layers Back To Top
It's Hot and Dry and You're Off For A Short Run
This one’s easy, get yourself a wicking base layer that will help your sweat evaporate and keep you cool.
It’s Hot and Dry and You’re Heading Off For A Half Day Hike Up Hill
Again, a good comfortable wicking base layer is essential but this time you need to take a second layer with you to protect you from the wind, when your activity levels fall and the wind picks up. Go for a light soft shell or a lightweight windproof that you can carry easily and bring out to keep the chill off.
It's Hot and Wet
If there’s rain about you need to replace your mid layer with a waterproof layer even though it might be hot. Keeping your core dry to prevent rapid cooling from wind chill is key. So you’re protecting yourself from the rain, the wind and your perspiration is moved away from your skin.
It’s Cold, Wet and Windy and You’re Off Into The Mountains
Ah, classic British conditions! This is where you’ll need to deploy the 3 main layers. Start with a wicking base layer, on top of that you’ll need a mid layer to insulate you, in really cold temperatures this should be a synthetic fill jacket (or down if its dry). Finally, you need your breathable waterproof.