Sun burn

Sun burnTypical first degree burn caused by short-wave sun radiation or artificial UV-radiationStages of burns:

1st degree: reddening and slight swelling of skin, pain, epidermis affected, comletely reversible

2nd degree: formation of blisters, intense pain, epidermis and dermis affected, complete regeneration (2a) or regeneration with scarring (2b, in case of deep involvement of dermis)

3rd degree: blac-white-necrosis, no pain because of destruction of nerve endings, dermis and subcutis affected, irreversible

4th degree: charring, no pain, all layers of skin and subjacent bone/fascia affected, irreversible

Source: wikipedia