Biological evolution has given us a mechanism that helps us defend our skin from the sun. As soon as UV rays get to the skin it starts producing melanin, a protein that �transforms� almost all UV rays that get to the skin into heat. Melanin makes our skin go darker and this is the way we get tanned.

The amount of melanin produced depends on the skin type each person has. It is known that people with fair skin and freckles have a phototype 1 skin and can get sunburns even by small amounts of sun. Black people have phototype 6 skin and they never get sunburns. Between these two types of skin, there is wide scale of phototypes.

The most frequent phototypes in the Mediterranean are:2 and 3 in the northern coast and 3 and 4 in the southern coast.