How to dress to stay warm when it’s super cold

The most important piece of advice, even if you ignore everything else on this page, is to dress in layers. Layers inherently intersect with most of the other items on this list.

Three layers keep you warm:

• base — Polyester, silk or any other material with the ability to wick sweat away from your skin. Just don’t use a cotton shirt as a base layer. It will absorb the moisture just fine, but it will not evaporate.
• Middle — This is the insulating layer, the workhorse to keep you warm. sweaters, sweatshirts, fleece; these will all work as the middle layer. It should be snug but not tight. Down jackets also make a great mid layer in the coldest temperatures.
• Outer — This layer is less about keeping you warm (the first two layers should do that) and more about keeping out wind and rain. If it’s not windy and it’s not raining, a regular winter coat (down puffer, wool pea coat, etc.) is fine. But if you really want to stay warm, turn your outer layer into a wind and waterproof layer, such as a raincoat. Ideally, it has vents around the armpits to allow sweat to evaporate. If you want to get really luxurious, the outer shells made of specially developed materials such as Gore-Tex or Sympatex are rain and windproof and also breathable.

Probably the most common misconception about dressing warmly is that the layers should be tight. But if you think of a layer of clothing as the interface between you and the elements, you can see how a tight shirt only brings your skin closer to the cold air.

Space keeps you warm: a well-fitting woolen sweater, for example, creates a thin boundary layer of air between your skin and the environment. Your body heat warms the boundary layer and the jersey prevents the layer from being blown away from your body.

Moisture is the kiss of death on a cold day, whether from rain or perspiration. Evaporation is a cooling process and when you are wet the cooling process happens directly on your skin.

Avoid getting wet by wearing a base layer that wicks sweat away from your body, such as polyester or silk. Your outer layer should be waterproof, like a raincoat, but also have vents or breathable fabric to allow your perspiration to evaporate from the inner layers.

Even if the temperature isn’t that cold, the wind can make your time outside miserable. Our warm bodies heat a small layer of air around us, which helps insulate against the cold. Wind can blow away the warm layer. The best way to fight the wind is with a windproof outer layer, which keeps the warm layer of air next to our skin, where it should be.

Protect your extremities by wearing a hat that covers your ears, waterproof gloves, and woolen socks. If you have a nice, thick head of hair, you can get away with earmuffs or a winter headband. The idea that most of your body heat is lost through your head is a myth. The body loses most of its heat through whatever is exposed. Stay covered and you’ll stay warm.

Materials and what they do

• Polyester or polypropylene — This material is actually fine, woven strands of plastic, which sounds awful to wear, but it can actually give clothing its softness. For example, fleece is usually made of polyester. Polyester and polypropylene are moisture-wicking fabrics that transport perspiration away from the skin. They make great cold weather clothing.
• Silk — It is more expensive than many other fabrics, but silk is a great material for a base layer because it is natural and wicks away moisture like polyester.
• Wool — This is an essential material for cold weather in combination with some layers of polyester. A wool sweater is a perfect intermediate layer. It does absorb moisture, which isn’t great, but it stays warm even when wet. The best thing about wool is its ability to trap that layer of warm air next to your skin. It also makes good hats and socks.
• Nylon — Nylon is good for outer layers because it doesn’t absorb much water. It makes a good poncho or raincoat.
• Gore Tex, Sympatex or similar — These are developed, patented materials that claim to be waterproof, windproof and breathable. Most of these live up to the claim. They are great outdoor jackets for cold weather.
• Cotton — Clothing made of cotton is not suitable for cold weather. It absorbs moisture and holds it next to your skin. Save the cotton for the summer when you might want some extra moisture to keep you cool.

This article has been updated since it was first published.