UV-protective clothing
How your outfit protects you from the sun
The sun on your skin feels good. However, when hiking, cycling, trail running or on high-altitude treks, UV radiation can quickly become a problem. This is exactly where UV-protective clothing comes in. It helps to block harmful UVA and UVB radiation before it reaches the skin. This is particularly important in the mountains, as UV exposure increases with altitude. What’s more, snow, glacier surfaces and light-coloured rocks reflect the radiation, meaning it hits the body not only from above but also from below.
What does UV protection in clothing mean?
UV-protective clothing is usually rated using what is known as the UPF value. UPF stands for Ultraviolet Protection Factor and indicates how much UV radiation passes through a fabric to reach the skin. For example, a shirt with a UPF of 50 allows only 1/50 of UV radiation to pass through. This equates to around 98 per cent protection.
Unlike sun cream, UV-protective clothing provides long-lasting protection for the areas of skin it covers, without you having to reapply sun cream. This makes it particularly practical for long hikes, hot summer days and alpine activities. However, it does not completely replace sun cream. Your face, neck, hands and legs are often left uncovered and should still be well protected with sun cream.
Why do some items of clothing offer UV protection and others don’t?
Not every T-shirt offers the same level of protection from the sun. A simple white cotton T-shirt can only provide a very low level of UV protection, whilst technical outdoor T-shirts often achieve significantly higher UPF ratings. The difference lies primarily in the composition of the fabric.
The weave plays an important role. The denser a fabric is woven or knitted, the less UV radiation can penetrate it. Very thin, loosely woven fabrics allow more radiation through. That is why many functional shirts offer better protection than lightweight everyday shirts, even though they feel pleasantly airy.
Colour also affects UV protection. Dark colours generally absorb UV radiation better than light colours. A dark T-shirt can therefore offer more protection than a white one, even if they are made from the same fabric. Whilst light-coloured clothing reflects light and often feels cooler, it can also let through more UV radiation, depending on the material.
What role do materials and technology play?
In modern outdoor clothing, UV protection is often provided by the fabric itself. Synthetic fibres such as polyester or nylon are often inherently more UV-resistant than many natural fibres. That is why brands such as Mammut, Dynafit, Schöffel, Norrona and The North Face rely on technical fabrics for many of their summer garments.
In addition, there are textiles in which UV protection is enhanced by special technologies. Some fabrics are treated with additives, whilst others contain ceramic particles or special coatings. These can help to absorb or reflect UV radiation more effectively.
It is important to note the difference between permanently integrated UV protection and post-production treatment. If the protection is embedded directly in the yarn or fibre structure, it generally lasts longer. If a garment is only treated on the surface, the protective effect may diminish over time, depending on how it is used, cared for and washed.
What can reduce the UV protection provided by clothing?
Even a good UV-protective shirt does not offer the same level of protection in every situation. Moisture can reduce the level of protection, as wet fibres often allow more radiation to pass through. This is particularly relevant when you’re sweating, doing water sports or after a rain shower.
Even heavily stretched fabric may offer less protection. If a shirt is very tight-fitting or stretched tightly in certain places, gaps open up in the fabric. This allows more UV radiation to reach the skin. For outdoor activities, it is therefore worth ensuring a good fit. The garment should fit comfortably without being constantly stretched tight.
Why is UV-protective clothing particularly important in the mountains?
UV protection is particularly important in the mountains. UV radiation increases significantly for every 1,000 metres of altitude. On glaciers, snowfields or light-coloured rock surfaces, there is also the added effect of reflection. As a result, UV radiation not only hits the skin directly from above, but is also reflected back from below.
For alpine tours, high-altitude hikes, walks and long days in the mountains, a functional UV shirt is therefore a sensible choice as a base layer. Combined with sun cream, sunglasses, a cap or a hat, it creates a protection strategy that is significantly more reliable than sun cream on its own.
Which UV-protective clothing is best suited to which activity?
Lightweight functional T-shirts with a high UPF rating are ideal for walks and mountain hikes. They dry quickly, wick moisture away from the skin and provide reliable protection for the areas of skin they cover. For particularly strong sunshine, long-sleeved T-shirts are recommended, as they also provide better coverage for the arms and shoulders.
Shirts offering very high UV protection are particularly useful for water sports or for children. Children’s skin is sensitive and should be protected as well as possible from direct sunlight. A UV shirt with a UPF of 50 or higher can be an important addition to sun cream and head coverings.
For everyday wear in summer, polo shirts, lightweight outdoor shirts or breathable long-sleeved tops with UV protection can be a good choice. They look sporty, feel comfortable and offer more protection than many classic cotton shirts.
Conclusion: UV protection starts with the right clothing
UV-protective clothing is more than just a summer trend. It protects the skin, makes long days outdoors more comfortable and is an essential part of your kit, particularly in the mountains. The key factors are the UPF rating, the fabric, the weave, the colour and the fit. Anyone who spends a lot of time outdoors should therefore think not only about sun cream, but also about the right outfit.
With a high-quality UV-protective T-shirt, a good hat, sunglasses and sun cream for exposed skin, you’ll be much better prepared for sunny outdoor adventures.