Wear thin clothes under your down jacket to keep warm! A super simple dressing trick, save it now

When winter comes, people who are afraid of cold want to put on all the clothes in the house. Not only do they wear down jackets, but they also wear sweaters, autumn clothes, and base clothes underneath, for fear that if they don't wear enough, the cold will penetrate into their internal organs through the gaps.

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But… the comfort level of wearing this way is directly below one star. It’s okay that my hands and feet are almost bloody, but it doesn’t seem to be warm at all! Compared to those people who can go out quickly with a short-sleeved shirt under their down jackets and can steam in the snow, it’s really a waste of suffering.

Isn't it said that you should put on more clothes when it gets cold? Then why is it that wearing more down jackets is not as warm as wearing less?

The secret to keeping warm is moderate fluffiness!

Our bodies are constantly generating heat, and due to the temperature difference between the human body and the external environment, we are also constantly dissipating heat. If the heat is dissipated too quickly and the heat generation rate cannot keep up, we will feel very cold. If there is almost no heat dissipation or the heat dissipation rate is slow, the heat we generate can be accumulated around the body, and we can naturally warm up.

Therefore, the essence of keeping warm is to reduce the loss of heat from the human body to the environment . The best way is to wrap yourself in something that conducts heat more slowly. So how do you determine the speed at which a substance transfers heat?
We can look at the index of thermal conductivity (also called thermal conductivity coefficient). Thermal conductivity is the amount of heat directly conducted per unit area and length of material under unit temperature difference and per unit time. Simply put, the lower the thermal conductivity of a substance, the slower it transfers heat and the better the insulation effect . Conversely, if the thermal conductivity is high, the heat transfer speed is fast and the insulation effect is poor.

The natural fibers such as down, wool, cotton, acrylic, viscose, polyester, etc. that we often use in warm clothing are all materials with relatively low thermal conductivity. But if we want to talk about the material with the lowest thermal conductivity in the world, it has to be still air .

Therefore, for a given piece of clothing, in addition to its own thermal conductivity being low enough, it also needs to be able to create an air layer of appropriate thickness and stability on the surface of the fabric. This powerful combination will provide a better thermal insulation effect.

The thermal insulation materials that are popular nowadays are basically good at creating stable air layers.

For example, down has a stable, three-dimensional structure with a large specific surface area, which can hold a lot of air. The down fibers on the down have a hollow structure and can store air. The combination of down flowers forms a three-dimensional structure that can store a lot of air. It is no wonder that no other daily material can compare to down in terms of warmth.

A down jacket that has been in the closet for a year is not as warm as it was the year before or is not warm after washing. This is because the three-dimensional structure of the down is destroyed and cannot store air. Use the air wash function of the washing machine or have it processed by the laundry to restore its warmth retention performance.

Man-made fibers are also optimizing their fiber structure to store more air. For example, polyester fibers (polyester), which are commonly used in cotton clothing filling, can be made into a three-dimensional structure that stores air by making the fibers into hollow structures and then into flakes, thereby improving the warmth retention of clothing. De-velvet, which has been very popular in recent years, has a special double T-shaped fiber structure that can store more air, so the thermal insulation performance of De-velvet is better than that of ordinary acrylic fibers.

The polar bear hair-like fiber recently published in Science is even more amazing. This new fiber imitates the hollow porous structure and dense shell of polar bear fur, creating more than 90% of pores inside the fiber, thereby achieving similar warmth retention properties to down, but the required material thickness is only 1/5 of that of down.

In short, no matter what kind of insulation material is used, the key to insulation is to create an air layer of appropriate thickness and sufficient stability .

Comfortable and warm, it's not difficult

When we wear clothes, in addition to the air stored between the fibers of the clothing material itself, the space between the layers can also store air. So does that mean the more layers there are, the more air is stored in the clothes, and the better the overall warmth retention is?

In fact, the air layer is too thick, and there will be a significant temperature difference from the inside to the outside of the air layer, which will cause air flow to produce heat convection . Once heat convection occurs, heat loss will be faster .

In addition to the heat convection caused by the temperature difference, too many layers will also squeeze the air layer . When the number of layers exceeds a certain value, the air storage between the layers of clothing will decrease as the number of layers of clothing increases.

This is actually easy to understand. If you wear a warm-up coat over your autumn coat, and a sweater over your warm-up coat, even if the size of the clothes you buy is large, the clothes will inevitably be squeezed tightly together, and there will not be much space for air to stay. Moreover, when we move, the squeezing and friction between the layers will further intensify the flow of air. Not only is the air layer compressed and thinned, but it also flows, and the thermal insulation performance is reduced by more than a little.

So, in addition to not wearing too many layers, don't wear too tight in winter, especially outerwear should be slightly loose. In fact, you can create an extra air layer in the inner layer to get better warmth . The comfort of wearing is improved, and the temperature is also increased.

Of course, a coat that is too big is not good either, after all, it is easy for the wind to enter, and the whistling cold wind will blow in from the collar and under the clothes, and no matter how good your clothes are, you can't keep out the heat. So in addition to the clothes themselves being good, don't forget to put a scarf on the collar to block the wind, and try to choose a coat with a slightly closed bottom to prevent wind from entering.

If you want to keep warm, you can use this formula to dress:

1. For the outer layer, choose down jackets, cotton jackets, cashmere coats, eco-friendly furs, jackets and other clothes with certain wind resistance. It is better if they can create a thicker air layer.

2. The middle layer is made of soft and fluffy polar fleece, fleece, thin cashmere, down liner, etc. to create an air layer. If the coat itself is warm and cold-resistant, you can directly remove the middle layer.

3. Choose moisture-absorbing and breathable close-fitting thermal underwear, quick-drying clothes, yoga clothes, etc. for the inner layer, which can quickly permeate moisture and breathe freely to prevent moisture generated by human metabolism from accumulating in the clothes, affecting the fluffiness of the outer layer and reducing the thermal insulation performance.

If you think this is too abstract, here are some specific outfits for you:

Super anti-freeze version (for blizzards at -15 degrees Celsius)

Men: thick coat (wool coat or down jacket) + wool sweater + base layer

Women: long down jacket + thin down liner + long-sleeved yoga clothes/fur + wool sweater + base layer

Source: Photographed by the author

Basic antifreeze version (for temperatures around -5 degrees Celsius)

Men: Wool coat + cashmere sweater + base layer

Women: long wool coat + ultra-thin down jacket (filled with about 30g) + long-sleeved spring clothes (anything is fine as long as the material is suitable)

Source: Photographed by the author

Be graceful and warm (to cope with above-zero temperatures)

Unisex: Thin coat + long-sleeved spring clothes

Source: Photographed by the author

In addition, whether the inner layer is suitable for pure cotton depends on the usage scenario . If it is just for daily wear and not a lot of exercise, a pure cotton inner layer is a good choice; if there is a lot of exercise and sweating, a pure cotton inner layer is not recommended. After pure cotton absorbs a lot of sweat, it will not only be uncomfortable to stick to the body, but also affect the overall warmth effect.

Pure cashmere or wool is highly recommended , but the price is not very friendly.

If you consider cost-effectiveness and easy maintenance, a blend of thermal insulation and moisture-absorbing materials is also a good choice. For example, blending materials with thermal insulation properties such as acrylic and polyester with moisture-absorbing materials such as modal, cotton, viscose, and bamboo fiber can achieve both thermal insulation and moisture-absorbing properties, and the price is also very friendly.

In addition to these, you should also try to avoid underwear with long fluff on the inside . Although long fluff looks warm, the long fluff traps moisture on the surface of the skin, which is not comfortable at all.

The same goes for the bottoms as shown in the outfit picture above. Because winter clothes are generally longer, two layers of bottoms are enough: the outer layer is windproof, and the inner layer is absorbent and breathable and also warm.

My usual combinations are as follows:

Thick jeans + moisture-wicking and warm thermal pants (slightly close-fitting, no need to be too tight) long skirt + plush stockings + leather boots In short, if you want to stay warm, it’s not just about piling up layers. You need to master the art of dressing for the air so that you can stay comfortable and warm from head to toe!

Planning and production

This article is a work of Science Popularization China-Starry Sky Project

Produced by Science Popularization Department of Science Popularization China

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author｜Xinshi Science Popularization Studio Science Popularization Team

Review｜Song Lidan China Textile Construction Planning Institute

Planning丨Yinuo

Editor: Yinuo