Sunburn is damage to the DNA within skin cells from ultraviolet (UV) radiation when the skin experiences too much unprotected exposure to the sun. The inflammatory reaction produced by the skin in response to the UV radiation damage is the outward sign of sunburn. Your skin produces melanin to block the damaging effects of UV radiation, which results in darkened skin color, commonly referred to as tanning. However, when your skin experiences too much UV radiation exposure, it cannot produce enough melanin, causing the affected skin cells to deteriorate and die. The inflammatory response, or sunburn, functions to replace the damaged and dead skin cells. Some individuals naturally have less melanin than others, owing to such factors as genetics and ethnicity. Consequently, such individuals are at higher risk of sunburns, as their skin does not have as many resources to fight off UV radiation damage.