By the time summer finally rolls around, most of us can’t wait to spend as much time as possible outdoors. That may explain why 35 percent of us get one or more sunburns a year. The familiar symptoms usually occur within the first 12 hours after too much sun exposure. There are two wavelengths: “UVA rays contribute to premature aging and play a role in the development of skin cancer, while UVB rays cause sunburns and have been linked to a major cause of skin cancer,” says Kalia. UVA activates melanin already present in your skin; UVB stimulates the production of new melanin as an initial defence mechanism, which creates the darker colour of a suntan. Many people can’t produce enough melanin for adequate protection. “Fair-skinned individuals who have red or blond hair and blue eyes are most at risk,” says Kalia, “but anyone can develop a sunburn.”
Once you have a sunburn, symptoms can get worse for up to 48 hours before the skin starts to heal, with full recovery taking one week or more. Not only can repeated sunburns accelerate skin aging, but a history ?of them, especially in childhood or adolescence, is also a risk factor for skin cancer.