Sunburn is an inflammation of the skin caused by overexposure to the ultraviolet (UV) rays of the sun. There are two types of ultraviolet rays, UVA and UVB. UVA rays penetrate the skin more deeply than UVB rays, and can cause melanoma in susceptible people. UVB rays, on the other hand, cause sunburn and wrinkling.

Skin cancer from sun overexposure is a serious health problem in the United States, affecting almost a million Americans each year. One out of 87 will develop malignant melanoma, the most serious type of skin cancer, and 7,300 of them will die each year.

Fair-skinned people are most susceptible to sunburn, because their skin produces only small amounts of the protective pigment called melanin. People trying to get a tan too quickly in strong sunlight are also more vulnerable to sunburn.

Repeated sun overexposure and burning not only cause cancer; it also can prematurely age...