Damage to skin caused by excessive exposure to the sun’s ultraviolet rays, comparable with a mild first-degree burn. It usually occurs as a result of sunbathing. The skin is normally protected against the rays of the sun by pigment which is formed when the pigment cells are activated by ultraviolet radiation. The skin then becomes tanned. Sunburn mainly occurs in the spring, when only small amounts of pigment have been laid down. The result is mild sunburn, with redness of the skin and pain. Second-degree sunburn can occur in serious cases, especially when someone has fallen asleep in the sun. In addition to the redness, blisters also form. Mild sunburn is not a serious condition, and heals without leaving any scars. It therefore requires no special treatment. The pain can be relieved by products applied to the skin after it has been exposed to the sun. Suntan oil and suntan lotion are of value only in the prevention of sunburn, not in its treatment. These preparations retard the ultraviolet rays, but do not soothe the pain. Severe sunburn is a serious condition, a form of sunstroke.