The sun is never totally absent even hidden behind a layer of clouds. Therefore it permanently emits ultraviolet (UV) radiation, which is classified into several categories according to its wavelength.
Differences between the different UV rays
UV-A (UV-age) are non-visible rays with a wavelength of 400 to 315 nanometers that are present regardless of the weather. These are the rays that penetrate deepest into the skin and are the cause of wrinkles and skin aging. UV-A rays are also responsible for the appearance of pigmentation spots and can cause skin cancer.
UV-B (UV-burning) are the ultraviolet rays responsible for tanning the skin. They have a wavelength of about 315 to 280 nanometers and penetrate less deeply into the skin. In addition to a beautiful tanned complexion, UV-B rays are the ones that cause sunburns and most skin cancers.
UV-C is the most dangerous of the sun's rays emitted by the sun. However, thanks to the ozone layer that filters out these rays, we don't have to worry about them.
Infrared rays are the rays responsible for the heat we feel when we are in the sun. These rays are the only ones we feel and when they are blocked by clouds we feel like we are sheltered from the sun, which is not true.
The ideal sun protection
When we are outside, UV rays attack our skin even if we don't notice it. UV-A and UV-B rays pass through clouds and are reflected by sand, water, snow and grass. Also, UV rays are not totally stopped by sunshades, so it is safer to protect yourself with clothes or sunscreen even in the shade.
In addition, the intensity of the sun varies according to several factors.
The closer the summer gets,
The higher the altitude,
The closer we are to the equator.
When choosing a sunscreen, it is important to check that it protects the skin from both UV-A and UV-B rays. UV-B protection is not sufficient because the skin is not protected from premature aging.
Sun protection for winter sports, the essential accessory
When winter is here, it's time to go to the mountains to enjoy the snow. Skiing, sledding, snowshoeing, walking or just having a drink on the terrace, as soon as the weather is right, everyone takes the opportunity to go out. But whatever the activity, a special winter sport sun protection is necessary.
Indeed, the mountain in winter is dangerous for two reasons:
The snow reflects most of the UV rays (up to 90%) even when the sun is not shining.
In the mountains, the intensity of UV radiation increases by 10% every 1000 m of elevation. It is therefore more violent for the skin than when we stay at home.
To protect yourself from this tenfold UV index, the best way is to protect your face and skin with a special winter sports sun cream to be applied every hour. Do not forget to protect your lips with a suitable balm because they are also sensitive to UV rays.
Guide to using sun protection
How long does sunscreen last?
Before applying sunscreen, it is important to check that it has not expired. When the shelf life of a cream expires, it means that the indicated sun protection factor is no longer guaranteed.
On many vials, the expiration date is written on the bottom of the bottle in months (6M, 12M, 18M, 24M). This indicates the storage time after opening the jar.
Some tips for a safe summer
In summer as in winter, protection of the skin against the sun's rays is essential to keep a beautiful skin all life long. Here are a few tips to follow to spend a summer in the sun.
Choose an SPF (Sun Protection Factor) that is appropriate for your skin. If you are unsure, it is best to choose a cream with an SPF of at least 30.
Be generous when applying and don't skimp on quantity.
Don't forget the ears, neck, feet, hands and lips.
Apply the cream every two hours and after swimming.
Avoid staying in the sun between noon and 3pm. These are the hottest and most dangerous hours for the skin.
Choose a waterproof sunscreen.
Cover your head and neck with a hat or scarf.
Check the expiration date of the cream before applying.
Children and babies have more sensitive skin than adults and should be covered with a hat or scarf to their skin.
At the end of the day, apply after-sun cream or moisturizer to soothe and rehydrate the skin.