Sunburn is skin damage caused by ultraviolet (UV) rays. It usually causes the skin to become red, sore, warm, tender and occasionally itchy for about a week.

The skin will normally start to flake and peel after a few days and will usually fully heal within seven days.

While sunburn is often short-lived and mild, it's important to try to avoid it, because it can increase your chances of developing serious health problems, such as skin cancer, in later life.

It’s easy to underestimate your exposure to the sun when outside, as the redness doesn’t usually develop for several hours, and breezes and getting wet (such as going in and out of the sea) may cool your skin, so you don’t realise you’re getting burnt.

You should always be aware of the risk of sunburn if you’re outside in strong sun, and look out for your skin getting hot.

What to do if you're sunburnt

If you or your child has sunburn, you should get out of the sun as soon as possible – head indoors or into a shady area.

You can usually treat mild sunburn at home, although there are some circumstances where you should seek medical advice (see below).

The following advice may help to relieve your symptoms until your skin heals:

• Cool the skin by sponging it with cold water or by having a cold bath or shower – applying a cold compress such as a cold flannel to the affected area may also help.
• Drink plenty of fluids to cool you down and prevent dehydration.
• Apply a water-based emollient or petroleum jelly (such as Vaseline) to keep your skin cool and moist.
• Take painkillers such as ibuprofen or paracetamol to relieve any pain – aspirin should not be given to children under 16.

Try to avoid all sunlight, including through windows, by covering up the affected areas of skin until your skin has fully healed.

When to seek medical advice

You should contact your GP, attend an NHS walk-in centre, or call NHS 111 for advice if you feel unwell or have any concerns about your sunburn, particularly if you are burnt over a large area or have any of the more severe symptoms listed below.

You should also see your GP if a young child or baby has sunburn, as their skin is particularly fragile.

Signs of severe sunburn can include:

• blistering or swelling of the skin (oedema)
• chills
• a high temperature (fever) of 38C (100.4F) or above, or 37.5C (99.5F) or above in children under five
• dizziness, headaches and feeling sick (symptoms of heat exhaustion)

Your GP may recommend using hydrocortisone cream for a few days (this is also available over-the-counter at pharmacies) to help reduce the inflammation of your skin.

Severe sunburn may require special burn cream and burn dressings from your GP or a nurse at your GP surgery. Very occasionally, treatment in hospital may be needed.

Who's at risk of sunburn?

Everyone who is exposed to UV light is at risk of getting sunburn, although some people are more vulnerable than others.

You're more likely to get sunburn if you:

• have pale, white or light brown skin
• have freckles or red or fair hair
• are only exposed to intense sun occasionally – for example, while on holiday
• are in a hot country where the sun is particularly intense

It’s also important to be aware that snow, ice or water can reflect the sun’s rays onto your skin, and that the sun is more intense at high altitudes.

Young children and babies are more sensitive to the effects of UV rays, and extra care should be taken to protect their skin.

Children and young adults in particular tend to spend more time outdoors, and overexposure to the sun at this age will increase the risk of skin ageing and skin cancer, even though this will only become apparent when they’re older.

It can be helpful to teach your child the importance of protecting themselves from a young age, as this may help it to become a lifelong practice.

Dangers of UV rays

The short-term risks of sun exposure are sunburn and sun allergy.

The longer-term risks (over decades) include:

• actinic (solar) keratoses – rough and scaly pre-cancerous spots on the skin
• skin cancer – including both melanoma and non-melanoma skin cancer
• eye problems – such as photokeratitis (snow blindness) and cataracts
• premature ageing of the skin and wrinkling

Preventing sunburn

In the UK, the risk of getting sunburnt is highest between March and October, particularly between 11am and 3pm, when the sun's rays are most intense.

There is also a risk of getting sunburn in other weather conditions. For example, light reflecting off snow can also cause sunburn. Beware that cloudy skies and cool breezes can make you feel cooler and underestimate how much sun you’ve been exposed to, but you may still be exposed to damaging levels of sunlight.

You can reduce your risk of sunburn by following the advice below:

• Avoid exposure to sunlight when the sun is strongest – stay in the shade as much as possible, cover up with loose clothing and a hat, and use sunscreen.
• Apply a generous amount of sunscreen 15-30 minutes before going out in the sun and reapply at least every two hours – even water-resistant sunscreens should be reapplied after you come out of the water.
• When buying sunscreen, choose one that has a high sun protection factor (SPF) – sunscreen with an SPF of 50 offers the best level of protection.

You should also wear sunglasses when out in the sun to reduce the risk of UV rays damaging your eyes.

Remember to take extra care with young children, as their skin is delicate and more easily damaged by the sun.

Read more about sun safety and protecting your skin.