The secret to staying warm on the trail isn’t wearing a single massive coat, worthy of the Michelin Man—it’s carefully bundling yourself in layer, after layer, after layer, after layer....
You may have heard of the “three-layer system” for outdoor clothing. It’s universal, It’s necessary. It’s life-saving. In our experience, however, it’s more like a four-layer system, especially if you don’t want to have a wardrobe full of individual pieces for specific activities.
First Layer: The One Directly Touching Your Skin
First goes your underwear, then your thermal underwear and that’s the layer we’re talking about. Remember babies and their onesies? It’s sort of like it. It’s a pair of leggings and a top, soft, warm and cozy as hell. If it’s not cozy, don’t bother.
One thing we love about thermal underwear is that it can double up as pyjamas, especially when they’re made of materials that don’t absorb the pungent yet unavoidable odors diffused by our bodies when we exercise.
The most popular materials are breathable synthetics, especially polyester. Merino wool is a good option because even when it’s wet, it can keep you very warm. We bought ours from L.L. Bean and the material is Merino wool. We love it but it’s just a tiny bit itchy, maybe a 1 on a scale of 1 to 10. We have washed it and it didn’t worsen, so it’s OK. A couple of our friends have Icebreaker thermal underwear and it seems to be slightly better quality.
Second Layer: The One that Is Your Actual Outfit
If you went into a rustic coffee shop or a pub in the middle of nowhere (we can only dream), you would probably remove everything except your pants, your t-shirt and maybe a light long-sleeve top. That’s your second layer.
It’s made up of your hiking pants, your polyester or Merino wool top (never cotton) and a long-sleeve top that is not too hot but adds a layer to cover your arms.
Third Layer: The One Whose Job Is to Be Your Personal Heater
Now the real work begins. Finding the perfect third layer is a labor of love. You need to look for the right material, the right fit, the right thickness... It might be easier to find your soul mate! Nevertheless, it is essential.
The jackets or sweaters that fit into this category are mostly made of fleece or warm synthetic materials. Depending on where you’re going, this could be your last layer. If you might be exposed to wind or rain, you’ll need an additional layer.
Fourth Layer: The One that Bravely Battles the Elements
Think of it as the layer that stands between you and the cruel world. If you’re not in cold conditions, this could be a light windproof jacket. If it’s raining a lot, it could be a warm rainproof jacket. If you’re in cold and wet conditions, you’ll be looking at a ski jacket. It’s most commonly referred to as the “shell.”
There are times that a third and fourth layer merge into one. That marriage can be a blessing or curse, as any marriage can be... What do I mean by this? Well, it’s always OK to be a little bit cold because if you’re hiking or climbing you might end up getting warm from all that exercise. But you might also need a light shell to protect you against snow, wind or rain.
If your jacket is waterproof but too warm, you’re screwed. You won’t be able to take it off but you’ll sweat, get tired faster, feel more uncomfortable than necessary and loose precious electrolytes. And your thermal underwear will probably smell by the end of the day. That’s why we usually carry a light rainproof jacket and a pair of light waterproof pants that go on top of your hiking pants.
Why You Should Never Buy Cotton
You may have noticed that I never mentioned cotton as a material for these layers. Apart from maybe using it for your actual underwear, it’s never recommended for two easy reasons: it gets wet quickly and it takes forever to dry. A recipe for discomfort in the best of cases and hypothermia in the worst of cases.
Do you have all your layers ready? If you need ideas on where to go on a shopping spree, check out my recommendations for outdoor stores in the countries we’ve visited.