What do you wear under a ski jacket? The layering system explained

Diagram of the winter sports layering system: base layer, mid layer and outer layer

You're at the top of the first run and it's minus eight. Halfway down you're sweating. On the lift back up you cool off and within two minutes you're cold. Sound familiar?

That's almost never your ski jacket's fault. It's what's underneath.

Why layers work and thick jumpers don't

One thick layer keeps you warm as long as you stand still. The moment you move, you sweat — and sweat that has nowhere to go will cool you down afterwards. That's exactly why you feel colder on the chairlift than you did on the piste.

Several thin layers solve that, because each layer has a different job. And because you can take one off when it gets too warm, which you can't do with a single thick jumper.

The three layers

1. The base layer: staying dry

This is the layer against your skin. Its only job: move sweat off your skin and outward. Think thermal underwear in merino wool or a synthetic fabric.

The classic mistake: a cotton T-shirt. Cotton soaks up moisture and holds on to it. You start the day fine and from ten o'clock you're sitting in a wet, cold layer you can't get rid of.

2. The mid layer: holding on to warmth

This is where the real work happens. The mid layer traps your body heat and keeps it there, while the moisture passed on by the base layer can carry on outward.

A ski pullover is exactly this. Not a thick woollen jumper, but a technical fabric that insulates and breathes. The zip at the neck is functional: you open it when you get warm, and it makes more difference than you'd think. Dropping a half-zip is the fastest temperature control you have.

3. The outer layer: keeping wind and snow out

Your ski jacket. It doesn't need to keep you warm — that's the mid layer's job. Its task is to block wind, keep snow out and still let moisture escape. That's why a good ski jacket is breathable and not simply waterproof.

The mistakes most people make

Too many layers. Four or five layers squeeze out the air in between, and it's that air doing the insulating. You also lose freedom of movement. Three good layers beat five random ones.

A hoodie as a mid layer. Understandable, but a cotton hoodie does the same thing as a cotton T-shirt: holds moisture. And the hood sits awkwardly under your jacket and helmet.

Too tight. If a layer pinches, there's no air left in between. You lose insulation exactly where you need it.

Keeping everything on at lunch. If you sit down indoors, take your jacket off. Otherwise you sweat in the hut and step back outside damp.

What to look for in a mid layer

  • Fabric. Synthetic or merino, not cotton. Our ski pullovers are 87% polyester and 13% elastane — breathable, moisture-wicking and with enough stretch to move freely.
  • A zip at the neck. Your quickest way to shed heat without taking anything off.
  • A fit that follows you. Not tight, but close. A flapping mid layer under your jacket doesn't work.
  • Odour control. You'll wear it for a week, usually without washing. A Polygiene treatment genuinely helps there.
  • A zipper garage. Small detail, big difference: a piece of fabric that stops the zip scratching your chin on the way down.

Adjusting to the day

The whole point of layering is that you can adapt. A sunny spring day in March asks for something different than a grey, windy day in January.

In mild weather you can often get by with a base layer and a ski pullover, carrying the jacket for the lift. When it turns genuinely cold, pick a thicker base layer rather than adding another layer on top.

The simplest advice: start your day slightly cold. If you already feel comfortably warm at the first lift, you'll be overdressed within ten minutes.

Finally

Your mid layer is the part most people think about least, even though it's the layer you wear all day and the one that decides how comfortable you are.

With us, that layer doesn't have to be dull either. Pick one from the collection, or design your own.

Browse men's ski pullovers · for women · or design your own