Sometimes you have to go outside when it is freezing cold, but the sun is still shining. Or its mid-summer, and pouring rain. But should you leave the sunscreen in the medicine cabinet?
It is important to block UVB and UVA with adequate sun protection. Risk for the skin is not linked to heat, but rather the intensity of UV light. We do not really notice their presence and need to be wary of the feeling of safety when the sky is cloudy or when it is windy.
UV radiation depends on several factors : the height of the sun in the sky, reflection off the earths surface, the latitude, cloud cover, altitude and ozone layer. Sea spray for example reflects up to 25% of incoming radiation, cloud cover can have the same effect by increasing the diffusion of the radiation.
The intensity of the UV radiation is related by a UV index. This index is a measurement scale of the intensity of the radiation established by the OMS. It ranges from 1 to 10. When the index is ranked between 1 and 2, there is low risk of radiation. On the other hand, a high number should alert about maximum risk. Sunburn risk starts at level 3.
This site shows the worldwide UV index, updated in real-time. Depending on the season, you can find out much UV your are being exposed to. Be careful in the spring, when skin that has not been exposed in months finally gets its first glimpses of sunlight.
Using daily protection, even low SPF will help avoid premature skin aging caused by excess UV.
Use of sunscreens in France is still too often limited to the 3 weeks of summer vacation. It is time to change our habits for the better and use sun protection adapted for the weather, even if we can not wait for it to get sunny again!