// BBC HEALTH NEWS — SALUTE
What are UV levels and how can you protect yourself?
As a period of extreme heat is forecast across the UK this week, UV levels are expected to be high in many areas.
Some exposure to UV is essential for our wellbeing, but too much is damaging and can cause skin cancer.
UV radiation is emitted by the Sun and penetrates the Earth's atmosphere.
It enables our skin to produce essential vitamin D, which is important for the function of bones, blood cells and our immune system.
It can lead to skin cancer by damaging DNA in skin cells. UV also plays a substantial role in skin ageing, contributing to wrinkles and loosened folds.
It has also been linked to eye problems, external, including cataracts.
"Every exposure to UV, especially every sunburn, increases our risk of skin cancer," says Prof Dorothy Bennett, from St George's, University of London.
"Melanoma, the most dangerous skin cancer, is now the fifth commonest cancer in the UK."
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