The best first layer in the mountains: thermal clothing

As is becoming increasingly common, more and more sportsmen and women are choosing to wear three layers for winter skiing and mountaineering activities. Before we go into the details of the first layer, it is worth remembering a little about the three-layer system:

• The first layer is the one that is attached to the skin, and its main purpose is to expel sweat from the body, and to maintain the warmth provided by the second layer.

• The second layer o the middle layer is intended to provide warmth to the body.

• The third or outer layer is prepared so that rain or snow does not wet the body, and to cut the wind. In addition to being waterproof, they must be breathable.

Therefore, when we talk about the inner or first layer, we are referring to the technical jerseys that are in contact with the skin.

The best fabrics: synthetic or natural fabrics?

In order for the sweat to dry more quickly, and for the T-shirt to be very comfortable, it is essential to choose the most suitable materials.

Undergarments or thermal clothing shall be made of synthetic or natural materials. 

Synthetic fabrics

The manufacture of thermal clothing with synthetic fabrics began around the 1970s. Since then, the evolution has been very favourable, and the performance of these garments has improved considerably. They are now more pleasant to the touch, more comfortable, and most importantly, they are highly resistant to the elements. hydrophobicThe sweat and moisture dries very quickly. In addition, they retain less and less sweat odour, so they can be worn comfortably for several days at a time. We are primarily looking for a moisture-wicking, quick-drying fabric with very good thermal propertiess, even in high humidity conditions.

The variety of synthetic fabrics is very wide: polyester, chlorofibre or polypropylene. We can highlight the Phasic SVwhich provides the garment with a high resistance as well as a high insulating power. There are many brands and technologies on the market. A good garment can be a T-shirt with base layerthe HH LIFA Crew (buy on Amazon from 30,45 euros). If the weather conditions are hot, look for short-sleeved technical T-shirts, with good breathability, such as the Miller ALPINE TS SS (click here to see).

Among the different brands we can highlight, with the best first layers for mountaineering:

• Helly hansenThe company has developed a number of pioneering technologies for its thermal clothing that have led to some flagship first layer garments. 

• PatagoniaThe brand is special not only because of its high quality fabrics, but also because it is in line with the leave no trace philosophy or footprint. This means that more than 90% of the materials used to manufacture the garments are recycled, and part of its revenue is directed to social and environmental campaigns.

• Odlois one of the leading brands in this field. They are pioneers in the manufacture of technical clothing for mountaineering and skiing. The quality of this brand is guaranteed by many professional sportsmen.

Merino wool

One can have the wrong image of wool. The wool of yesteryear that was used to make thick or coarse socks or jumpers is a thing of the past. Nowadays, the way natural wool is treated makes it one of the most valued materials for sportsmen and women. In the following article we talk about the merino wool clothing in the mountains (click to see).

Sophisticated technologies have made garments out of this natural fabric that can be even more durable. better than synthetic T-shirts. However, the manufacture of these garments requires a great deal of work which is delicate and costly. Consequently, the prices of these garments are quite high. But in case you want to buy a woollen garment, it is more than advisable to pay what is necessary. Low quality imitations do not have the same performance. If you do not want to spend too much, it is better to opt for a synthetic fabric.

The best advantages of woollen garments are the following:

• Unlike synthetic materials, do not retain odourThey can be used for days at a time without having been washed.

• Regulates body temperature in a natural way. Garments made from merino wool are suitable for both warm and cold days. They are able to maintain a balanced body temperature. They have a high heat capacity, but are also breathable.

• Dries fast. They may dry less effectively than synthetic fabrics. However, its ability to dry sweat is much greater than cotton garments.

• Maintains its properties even if wet. This fabric will continue to be a natural thermoregulator whatever their status.

• It is flame resistant, UV resistant, and does not cause static discharges caused by synthetic fibres.

One of the best brands that manufactures this type of garment is Devold (Click to view articles). This Norwegian brand has been working with high quality wool for more than a century and a half. Some of the milestones and feats that have taken place at the poles have been worn by this brand. The wool used is from a merino sheep breed which is quite abundant in Australia.

Thickness of thermal mountain clothing

Depending on the thickness of the garment we will have a greater or lesser capacity to conserve body heat. The thickness of the garment is measured in g/m2.

For a multi-purpose thermal garment for the mountains we will go to 180g/m2The thickness of the fabric, which will be valid for cold environments in winter, spring and autumn. For more extreme cold we will have to go to higher thicknesses. 

Advantages and importance of thermal clothing

Wearing an under layer is essential whatever the weather. Whether it's raining, snowing, or snowing, your body sweats, and your jersey needs to be ready to wick that sweat away quickly.

There is no point in having the best garments as second and third layers if the first layer does not meet the basic conditions. A mistake that many people make is to wear cotton T-shirts, which are used for walking in the street, for active sports. This material is not designed to dry sweat quickly. Once they get wet, it is very difficult to dry them. In addition to the fact that they become heavy, they tend to cool the body. When we are doing the activity with great intensity it is not usually noticed, but when we stop the wind cools the sweat and consequently cools the body.

In the high mountains, poor choice of undercoat can lead to hypothermia. In addition, a wet T-shirt is not at all comfortable. Consequently, thermal clothing prepared for sports should have the following basic characteristics:

• Having highly hydrophobic. This means that the fabrics tend to dry relatively quickly. The function should be to wick sweat away from the skin and maintain body temperature by preventing the body from cooling down.

• To be convenient and comfortable. A first layer should not hinder the movements of the trunk and arms. In addition, the seams of low-quality garments can cause chafing in sensitive areas of the body. Make sure you buy a T-shirt with certified quality. The design should be stretchy and close-fitting and provide great freedom of movement.

*All purchase prices included in this article are current as of 27/11/2018.