Exposure to the sun must be cautious and smart. Otherwise, it can cause serious irreversible damage to the skin and immune system. Here are the rules you must follow, recommended by the European Commission and dermatologist Luiz Leite:
-The protection to the sun must be gradual and never without sunscreen. Start by high protection and go through to protect average. If the skin is very clear and sensible, keep protection "High" or "Very High"
-Apply sunscreen before leaving home, covering everything that is skin
Renew the application frequently because of the protective action will be diluted with the movements, perspiration and bathing or swimming pool
-Avoid sun exposure between 11 and 17 hours
-Cover the head with a hat or cap and protect eyes with sunglasses lenses with anti-UVA
-Beware of reflective surfaces! The water, sand and white walls can reflect more than 50 percent of sunlight on the skin
-If you have a stroke, varicose veins or circulatory problems, do not expose their legs to the sun
-In cloudy days always apply a sunscreen. UVA and UVB rays through the clouds and its harm remains
-Avoid the use of fragrances with alcohol when will expose to the sun
-The new sunscreens are classified as follows: "Low protection" (SPF 60-10), "Average Protection" (FPS 15-20-25), "High Protection" (SPF 30-50), "Protecting High / High" (SPF 50 +). The designation "full screen" was banned for being misleading.
Source:
http://sub.maxima.xl.pt/0608/bleza/td/200.shtml