The skin’s reaction to the ultraviolet radiation (UV) in sunlight, sunburn is actually a first degree burn, and often accompanied by the familiar symptoms of tender, reddened skin. More severe burns, with bright red colouring, swelling and blistering indicate that the burn has penetrated the surface layer of the skin and become a second degree burn.
What causes sunburn?
The sun has two types of ultraviolet radiation important in a discussion of damaging effects to the skin. It is UVB rays which cause sunburn and the potential for skin cancer, although UVA radiation is now also considered to contribute to premature ageing and wrinkling.
Reflected sunlight from sand, water or snow can also cause sunburn. Certain drugs can also intensify the harmful effects of UV radiation.
Fair skinned people are more vulnerable to sunburn than darker people, but it is possible for anyone to get burnt if they are exposed for long enough at a time or place when the UV levels are high.
Few cases of sunburn require medical care, however extremely severe cases of sunburn (those involving extensive blistering, dehydration, or fever) usually require medical attention.