Sunburn and other sun reactions of the skin
Sunburn is the skin's reaction to too much exposure to ultraviolet (UV) rays from the sun.
Depending on skin type, this can make the skin go red, become painful, blister or peel. This reaction is the body's way of starting to repair the damage, by blood vessels swelling and bringing more blood to the damaged area.
A person with severe sunburn may also experience chills, a fever, generally feel unwell or malaise, nausea, headaches or dizziness.
Someone with severe symptoms of sunburn over a large area of skin, or sunburn on a young child or baby, requires medical attention.
Babies and children, and people with fair skin or red or blonde hair are generally at a greater risk of sunburn. So are people who don't go out in sun often, as their levels of melanin pigment in the skin will be lower, which increases the risk of burning more quickly.
Some medicines or herbal remedies can increase a person's sensitivity to sunlight, known as photosensitivity.
People who are severely sunburned may develop a raised temperature, chills and/or weakness. In rare cases, people with sunburn can go into shock (very low blood pressure, raised pulse and impaired consciousness).
Long-term skin damage from the sun or sunbeds can affect a person's skin cell DNA and may lead to skin cancer.
UVB rays cause most sunburns and can cause skin cancers. UVA rays go deeper into the skin and are responsible for signs of ageing, and can contribute to skin cancer developing.
Even on cloudy days, some UV radiation reaches the earth and can cause skin damage after a period of time.
Sunburn isn’t just something to worry about when on holiday in a hot place abroad. Cancer Research UK says more than half of people from the UK who suffer from sunburn get burnt here at home. Sunburn isn't just a concern for sunbathers. Just being outdoors exposes a person to UV rays.
Sun can also be reflected off snow meaning winter sports enthusiasts also need to take sun precautions.
To protect against UV rays, stay in the shade, cover up with appropriate clothes, hats and sunglasses, and use sunscreen with a protection factor of at least SPF15, and re-apply it often.
Not all sun exposure is bad
The risk of sunburn doesn't mean that all sun exposure is bad. The body needs some exposure to sunlight to help produce vitamin D for healthy bones. Because everyone is different, experts haven't been able to recommend a set amount of time to be in the sun. However, a group of health charities, including Cancer Research UK, says regularly going outside without sun protection for a matter of minutes in the middle of the day should be enough, always taking care that the skin doesn’t redden or burn.