Improvising sun protection: shade, cover, neck protection

Sunlight contains visible light, thermal radiation and invisible UV radiation. Thermal radiation heats skin and clothing, and the body has to get rid of that heat again, mainly by sweating. UV radiation, on the other hand, hardly warms you but damages skin and eyes. Because you cannot feel it, you can get sunburnt even on cool, windy or cloudy days – clouds let part of the UV radiation through.

Fabric protects by catching radiation before it reaches the skin. Densely woven fabric lets less through than thin or loose fabric, or stretchy fabric that fits tightly and pulls its weave apart. A simple test: hold the fabric up to the light. If you see a lot of light through it, a lot of UV radiation gets through too. You cannot determine exact protection values this way, though.

With shade, the air is what matters. A roof directly above the body heats up and radiates the heat back down. A shade roof with space above the head and open sides lets warm air escape and cooling air flow through. Two layers with an air gap in between cool even better, because the top layer catches the heat and the lower one lies in the shade of the top one.

Shade first: use natural shade from trees, rocks or buildings, or rig a tarp high and angled with open sides. An umbrella gives shade while walking too. Cover as much skin as possible with long, loose, densely woven clothing. Light colours heat up less.

The neck, ears and face are forgotten especially often. A T-shirt or cloth on your head, with the neck opening around your face and the fabric over neck and shoulders, protects exactly these spots. With a cap or a cord over it, it stays in place even in the wind.

The time of day is a powerful tool. Around midday UV radiation is strongest and the heat often greatest. Put exertion into the cooler morning and evening hours and rest in the shade at midday. A simple rule of thumb: if your shadow is shorter than you are, UV radiation is particularly strong. Drink regularly and keep your water in the shade.

Heat can make you ill. Warning signs are severe tiredness, headache, dizziness, nausea and muscle cramps. Then: get into the shade straight away, take a break, loosen clothing, cool with water and drink. Confusion, altered consciousness or collapse may be heatstroke – a life-threatening emergency. Call the local emergency number (112 in the EU), move the person to shade and cool them until help arrives.

Children and older people are especially sensitive to heat and often notice thirst less. Actively offer them shade and drinks. Infants do not belong in direct sun. Never leave children or animals in a parked car – it heats up strongly and quickly in the sun.

The eyes need protection too. Snow, water and bright sand reflect a lot of light, and UV radiation is stronger at altitude. This can lead to snow blindness, a painful inflammation of the surface of the eye that often only becomes noticeable hours later. Sunglasses with UV protection therefore belong in your pack; improvised slit goggles made from card or cloth are only a stopgap.

You are waiting outdoors for help, after a breakdown or on a hike, say, and there is no shade. Then rig a tarp, a blanket or even a jacket between the car and the ground, sticks or backpacks – as high as possible, with open sides. Do not sit on hot ground; sit on a mat.

On the water, in snow or in the mountains the sun is easily underestimated because it feels cool or windy. Yet this is exactly where UV radiation is especially strong due to reflection and altitude. Cover your skin, protect your neck and wear sunglasses.

In dry heat a damp cloth on the neck can cool pleasantly, because evaporating water carries heat away. But do not use drinking water for this when it is scarce – drinking always comes first.

Health authorities such as the WHO name shade, avoiding the midday heat and drinking enough as the cornerstones of heat protection. Travel medicine advice adds covering clothing, a hat and sunglasses. Improvisation helps when gear is missing – but it does not replace planning water, route and times of day.

A common misconception is that a light, tight shirt protects well from the sun. Thin, stretched fabric in particular often lets a lot of radiation through. And another misconception: if you are not sweating or thirsty, you do not need to drink. In dry heat sweat evaporates so quickly that you hardly notice it.