A Guide To The Layering System

What is the layering system?

A “layering system” is a way of dressing for cold weather that effectively balances the competing needs of insulation, mobility and breathability. This typically consists of three layers, a base layer, mid layer and outer layer, consisting of a “shell” or insulated jacket — although this will depend on the environment, conditions and activity you’re getting involved in.

Get it right and the optimum layering system will keep you warm, dry and comfortable in adverse conditions, allowing you to complete the task at hand. Get it wrong, and you will either freeze or overheat, and excessive sweating will cause your body temperature to plummet dramatically in cold climates.


How does the layering system work?

Layer one

Base Layers

The most effective barrier against the cold starts with a high-quality base layer. Here the key consideration is moisture management, as your next-to-skin layer you will need something that is capable of wicking sweat away from the body. This will keep you comfortable during periods of high activity and prevent your body cooling too dramatically in cold conditions.

Whether you prefer natural fibers or synthetic, the light feel of our Stealth Merino Layer or require something thicker such as the Siege Base Layer for the extreme cold, our current range offers you the choice of both.


Mid Layers

A flexible mid layer can be one of the most useful pieces of kit in your expedition armoury. What you need is a mid-layer that can regulate your temperature, keeping you warm during periods of low activity but breathable enough to prevent you overheating as you ramp up the exercise.

Additional qualities like wind and water resistance will help widen a reliable mid-layer to a dependable, year-round layering option. Our range of mid-layers, constructed from carefully-selected smart-synthetic fabrics, are designed to do all this and more. Choose from our iconic Phalanx Fleece, best selling Mantra range, or our Apex award-winning Centurion Jacket.


Outer Layers

As an “Outer Layer” you will generally look to a “Shell” or “Insulated” Jacket for the final line of defence against cold, wind or rain.

A “shell” jacket is typically designed to be waterproof and/or windproof, prioritising hostile weather protection over insulation. The reason being, shell jackets are usually intended for periods of high activity where your body is already generating more heat than when stationary. That being said, it is often advised to layer a shell jacket over an insulated mid layer and/or base layer for additional warmth in cold environments and stop/start periods of activity.

As the name suggests, “insulated” jackets are primarily concerned with keeping you warm. Packed with down fill or synthetic insulation, insulated jackets will often be windproof but are rarely waterproof. That’s because waterproof fabrics can lack breathability (which you want in an insulated jacket to prevent overheating).

Best left to extreme cold environments, insulated jackets work well for sub-zero temperatures and slower pursuits where your body is not generating as much heat.

Which outer layer is right for me?

As the name suggests, “insulated” jackets are the warmer of the two as they are typically packed with either down fill or synthetic insulation. Designed to trap the heat generated by your body, insulated jackets are better suited to more extreme cold and/or more stationary pursuits and periods of lower activity. Put simply, if you’re going to be standing around in the cold for long spells of time, it’s an insulated jacket you want.

Should it always be three layers?

A layering system does not always need to be three layers (a base, mid and outer) as requirements will vary by activity and environmental conditions, as well as your own individual preferences and whether you tend to run cold or hot.

For example, when hiking on a mild day with little or no wind, a light base layer and insulated mid layer will likely do what you need — although it always pays to pack a hardshell in your backpack in case the weather suddenly changes.

Otherwise, if you generally run hot you might find you operate best with a base layer and an insulated jacket in cold temperatures and forgo the additional insulation of a fleece mid layer.


With the rest of your body wrapped up in layers, any remaining body heat will escape through your head. Therefore, the final piece in your cold weather layering system should always be a beanie, preferably wool. Easily packable, a beanie will make all the difference in colder climes at a minimal carry burden. You can thank us later!

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