Exposure to ultraviolet or UV rays is what cause sunburn. UV rays penetrate to the deeper layers of the skin where they damage and/or kill skin cells. People with less melanin burn easily, these people especially should protect themselves by covering up and wearing an SPF of 30 or higher.
Melanin, the cells that contain pigment, protects skin from the sun’s ultraviolet rays responsible for burning the skin. Continued exposure reduces its elasticity and contributes to premature aging.
Frequent and prolonged exposure to ultraviolet rays over many years is not the only cause of skin cancers, it is possible that even one severe burn could result in the formation of cancerous cells.