Sunlight has 3 parts: visible light, infrared (this is the bit that makes it feel warm), and ultraviolet (UV).
UV gives us vitamin D, is thought to lower blood pressure (which explains why there are less high blood pressure issues in the summer), but it can also burn and give us skin cancer.
Sunburn is the skin’s inflammatory response to too much UV radiation The skin cells DNA is damaged, the cells die and the tissue is replaced.
Sunburn isn’t just about red skin. Blisters, itching, being sick, fever, chills and fainting can also be part of the fun. It is not that uncommon for serious cases to put people in hospital