Sun Safety: Sunscreen, SPF and UV for the Family

Use a sunscreen with a sun protection factor (SPF) of at least 30, and make sure it also carries 4 or 5 star UVA protection. That is the NHS recommendation for adults and children alike, repeated across official guidance from England, Wales, Scotland and Northern Ireland¹. Apply it generously before you go out, reapply it frequently, and reapply it straight after swimming, sweating or towelling dry¹.

Sunscreen alone is not enough. The Welsh Ambulance Service is blunt about it: do not rely on sunscreen alone to protect yourself from the sun². Combine it with clothing, a hat, sunglasses and time in the shade, especially between 11am and 3pm, when UV levels are at their highest¹. And remember that this is a UK problem, not just a holiday one: the sun's rays can be strong enough to burn in the UK from around April to September, and in many cases sunburn actually happens here at home, often when people are out and about³.

This page sets out what the official advice says for families: which sunscreen to choose and how to use it, how to cover up, how the UV index works and where its forecasts fall short, how to recognise and treat sunburn, and when to stop treating it at home and get medical help.

What SPF sunscreen should I use?

The NHS recommends a sunscreen with a sun protection factor (SPF) of at least 30 to protect against UVB, and at least 4 star UVA protection¹. The two ratings do different jobs, and you need both. SPF measures protection against UVB, the radiation that burns the outer layer of skin. The star rating measures protection against UVA, which penetrates deeper and contributes to skin ageing and skin cancer. Northern Ireland's official advice puts it the same way: experts recommend a sunscreen with an SPF of at least 30 and a UVA rating of four or five stars⁶.

Choose a broad-spectrum brand, one that protects against both UVA and UVB rays⁷. Most sunscreen designed for children has an SPF of between 30 and 50 and is effective against both UVA and UVB, so a child-specific product is not essential as long as the ratings are right⁸.

How you apply it matters as much as the number on the bottle. Apply sunscreen generously and reapply it frequently, especially after swimming or towelling¹. Guy's and St Thomas' NHS Foundation Trust advises applying sun cream before going outside in the sun, not once you are already out in it⁹. For babies, NHS guidance is to use plenty of sunscreen and apply it regularly, every 2 hours, reapplying immediately after swimming or sweating¹⁰. Check the expiry date too: Warwickshire County Council's summer advice is to make sure sunscreen is at least factor 30, not past its expiry date, and applied regularly when outdoors¹¹.

You will see lower figures in some places. A few local resilience and medicine-cabinet guides list SPF 15 or higher as a minimum¹², and NI Direct's first aid guidance suggests sun block of factor 25 or higher for children¹⁴. These are not wrong, but they are the floor, not the target. Where the NHS speaks directly, its recommendation is SPF 30 with 4 or 5 star UVA, and that is the figure to shop for¹.

Cover up and stay in the shade as well as using sunscreen

Sunscreen is one layer of protection among three. The Met Office's advice is to protect yourself and your family from sunburn by using a combination of shade, clothing and at least SPF 30 sunscreen³. The Welsh Ambulance Service says the same: do not rely on sunscreen alone; wear suitable clothing and spend time in the shade when the sun is at its hottest².

Timing matters most of all. UK Health Security Agency guidance for hot weather is to try to stay in the shade between 11am and 3pm, when UV levels are highest, and to try to avoid direct sunlight in that window¹. NI Direct's heat exhaustion advice matches it: keep out of the sun between 11.00 am and 3.00 pm¹⁵.

What to wear, from the official guidance:

• Lightweight, loose-fitting, light-coloured, close-weave clothes¹
• A wide-brimmed hat, or a peaked cap, to protect the face and head¹
• Wraparound or wide-armed sunglasses, to reduce UV exposure to the eyes¹
• Sunscreen on the areas clothing cannot cover: face, ears, feet and backs of hands¹⁷

For children, NHS guidance for the UK is specific about the season as well as the hours: from March to October, children should cover up with suitable clothing, spend time in the shade particularly from 11am to 3pm, and wear at least SPF30 sunscreen applied to areas not protected by clothing¹⁷. Government guidance for schools and early years settings in England adds that children should have sunblock or broad-band sunscreens with high protection factors, of at least SPF 30 and a UVA rating of 4 or more stars¹⁸.

If you are planning around hot weather more broadly, our heatwaves and drought guide covers the whole picture, and how to keep your home cool in hot weather helps with the hours when you are indoors.

You can burn in the UK, not just on holiday

NHS guidance is unambiguous on this point:

The Met Office adds the detail on timing: the sun's rays can be strong enough to burn in the UK from around April to September³. That is a six-month window, far longer than most people assume, and it covers the school run, the allotment, the weekend walk and the sports field as much as the beach. In many cases sunburn actually happens in the UK, often when people are out and about rather than deliberately sunbathing³.

Cloud changes less than people expect. The sun is often strong enough in the UK to cause sunburn even when it is cloudy¹, and the UV index can be strong through cloud even when the sun is not directly shining¹⁹. So the habit worth building is not "sunscreen on sunny days" but "sunscreen on exposed skin from spring to autumn", with NHS 111 Wales guidance noting you should cover exposed parts of your child's skin with sunscreen even on cloudy or overcast days⁸.

Temperature is a poor guide too. The UV index can be high at many times of the year; it does not have to be hot, and there may be cloud cover²⁰. A cool, bright April day can carry enough UV to burn unprotected skin.

How UV damages skin and raises the risk of skin cancer

Sunburn occurs when your skin is overexposed to UV radiation²⁰. The damage is not just to the surface. The Met Office explains the mechanism: excessive UV radiation directly damages the DNA in your skin cells, and if that DNA does not correctly repair itself, this can lead to skin cancer²⁰. Continued overexposure dramatically increases the risk of developing skin cancer²⁰.

That is why the official advice treats every burn as meaningful, not just the severe ones. Even brief exposure to the sun can cause sunburn and increase your risk of skin cancer²¹. Overexposure to the sun is dangerous in a range of ways, with effects ranging from mild sunburn to skin cancer, and it does not have to be hot for the UV index to be high¹⁹.

There is no safe way to acquire a tan, and a tan does not protect your skin from the sun's harmful effects⁴. This matters for teenagers in particular, who may see tanning as protective or harmless; the guidance says otherwise, and the DNA damage that leads to skin cancer accumates across years of exposure.

Checking the UV index forecast

The UV index is a measure of the strength of the sun's ultraviolet radiation, and the Met Office publishes a UV forecast for the UK alongside its weather forecasts. It is the most useful single check before a day outdoors, because it tells you the risk directly rather than leaving you to guess from temperature or cloud.

Two things are worth knowing about how the forecast is made, because they change how you should use it.

First, the UV index can be high at many times of the year; it does not have to be hot, and there may be cloud cover²⁰. Check it from spring onwards, not only during heatwaves.

Second, the forecast has a known limitation around ozone. The Met Office's UV model currently accounts for sun angle and forecast cloud amounts, but uses a "climatological" value, meaning the average concentration for the time of year over the UK, to estimate the total ozone concentration³. During low ozone events, the UV index could be higher than currently indicated in the forecasts, particularly if forecast cloud amounts are low, and the forecast can still be lower than actual levels despite the Met Office rounding up its UV values³. The Met Office is exploring ways to incorporate low ozone events into its models to improve the UV index forecast³. Until then, treat the forecast as a floor rather than a ceiling: protect skin on moderate-forecast days as well as high ones.

During heatwaves, the UV risk sits alongside heat itself. Our pages on heat-health alerts and heat exhaustion and heatstroke cover the heat side of a hot day.

Sunburn in babies and young children

Young skin needs the same protection as adult skin, applied more carefully. NHS guidance for babies is to apply a sunscreen with an SPF of at least 30 that protects against both UVA and UVB rays, and to reapply it regularly¹⁰. If your baby is 6 months or over, apply a sunscreen with a sun protection factor (SPF) of at least 30 to their skin¹⁰. Use plenty of it and apply it regularly, every 2 hours, reapplying immediately after swimming or sweating¹⁰.

For children, the same SPF 30 minimum applies, with UVA and UVB protection and regular reapplication²³. Most sunscreen designed for children has an SPF of between 30 and 50 and is effective against UVA and UVB⁸. From March to October in the UK, children should cover up with suitable clothing, spend time in the shade particularly from 11am to 3pm, and have sunscreen applied to the areas clothing does not cover, such as the face, ears, feet and backs of hands¹⁷.

Children burn without noticing, because they are busy. NHS guidance for children lists what sunburn looks like: the skin may feel hot to touch, feel sore or painful, and flake or peel a few days afterwards; severe sunburn may blister²³. If a child under 5 has sunburn, call your GP, NHS 111 or 999 to seek medical advice, or if you are worried at any age²⁴. Our page on keeping babies and young children safe in hot weather covers the wider heat risks for the youngest, and how to treat sunburn, including in children goes deeper on treatment.

Signs of sunburn: what to look for

Sunburn does not always announce itself at the time. Most people initially experience mild symptoms, such as hot red skin and fatigue²⁰. NHS guidance for children adds that the skin may feel hot to touch, feel sore or painful, and flake or peel a few days after the sunburn, and that severe sunburn may blister²³. Being exposed to the sun for too long can cause painful sunburn²⁵.

The practical point for a household is that the person who "feels fine" at 2pm may be in pain by the evening. Do not wait for symptoms before acting: get children out of the sun at the first sign of reddening, and treat the day's exposure as done.

Sunburn usually gets better in 7 days⁵. Flaking and peeling in that window are normal; blisters, swelling and feeling generally unwell are not, and they are the signals to move from self-care to medical help.

Treating sunburn: cool the skin

The first-aid sequence from NHS guidance, in order:

1. Get out of the sun as soon as possible²³
2. Cool the skin with a cool shower, bath or damp towel²³
3. Apply after sun cream or spray²³
4. Drink plenty of water²³
5. Take painkillers such as paracetamol or ibuprofen if needed²³
6. Cover sunburnt skin from direct sunlight until it has healed²³

On cooling, the guidance gives slightly different figures, and it is worth knowing both. NHS 111 Wales advises taking a cool bath or shower for 10 minutes to cool down the burnt area of skin⁸. Other NHS burns guidance goes further: cool the burn with cool or lukewarm running water for at least 10 minutes²⁴, or for 20 to 30 minutes²⁶. The Welsh Ambulance Service offers the same range of methods for mild sunburn treated at home: cooling the skin with a cold bath or shower, sponging it with cold water, or holding a cold flannel to it¹⁶. Then apply soothing after sun cream or spray².

After sun cream or spray is part of the standard treatment, not an optional extra: sponge sore skin with cool water or take a cool shower or bath, then apply soothing after sun cream or spray². It soothes the skin but does not reverse the underlying damage, which is why prevention carries the weight in all of this guidance.

Once burnt, the skin needs protection while it heals. NHS Inform's burns guidance is to keep the area covered with cotton clothing, wear a peaked cap or wide-brimmed hat if the burn is on your face, and use sun cream with a high sun protection factor²⁷. Burnt skin is more vulnerable to further damage, so the recovery period is not a licence to skip the sunscreen.

Pain relief: paracetamol or ibuprofen, never aspirin under 16

For the pain of sunburn, NHS guidance is straightforward: take painkillers such as paracetamol or ibuprofen²³. NHS 111 Wales says the same: if you have any pain, paracetamol or ibuprofen should help relieve it⁸.

This matters at the point of use, not just at the point of purchase: many household medicine cabinets contain aspirin alongside paracetamol and ibuprofen, and on a hot, painful evening it is easy to reach for the wrong packet. Leicester, Leicestershire and Rutland's NHS guidance on what to keep in your medicines box makes the distinction explicit: pain relief means paracetamol, ibuprofen, and aspirin, which mustn't be given to children under 16²⁸.

While you are treating the pain, keep up the fluids. Drinking plenty of water is part of the sunburn treatment sequence²³, and it matters because sunburn and heat illness often arrive together on the same day. Our page on dehydration in hot weather covers the signs that someone is not drinking enough.

When sunburn needs medical help

Most sunburn can be treated at home, but there are clear thresholds for getting help. The Welsh Ambulance Service's advice: seek medical help if you feel unwell or the skin swells badly or blisters². NHS guidance adds that you can get help from NHS 111 for advice about a burn or scald at any point where you are unsure²⁶.

For children, the list of red flags is longer. Seek emergency medical care if a child's sunburn causes blisters or is extremely painful, causes facial swelling, covers a large area, or if the child has fever or chills, headache, confusion, faintness, or signs of dehydration such as increased thirst, less pee, or dry eyes and mouth²³. And if a child under 5 has sunburn, call your GP, NHS 111 or 999 to seek medical advice, or if you are worried at any age²⁴.

In Wales, you can also visit the NHS 111 Wales website for further advice². Our page on when to call 999 or NHS 111 for heat illness covers the emergency end of the same spectrum, and heat exhaustion and heatstroke explains the signs that the problem is heat rather than sunburn.

Getting into good habits before the summer

Sun safety works best as a routine rather than a reaction. The recurring advice across every official source is the same small set of habits: sunscreen of at least SPF 30 with 4 or 5 star UVA protection, applied generously before going out and reapplied every couple of hours and after swimming¹; shade between 11am and 3pm¹; clothing, a wide-brimmed hat and wraparound sunglasses¹; and a check of the UV forecast, remembering that it can underestimate on low ozone days³.

A few practical checks before the season starts:

• Sunscreen in the cupboard is at least factor 30 and not past its expiry date¹¹
• It carries 4 or 5 star UVA protection and covers both UVA and UVB¹
• The medicine cabinet has paracetamol and ibuprofen, and aspirin is kept away from children under 16²⁸
• After sun cream or spray is in stock for treatment²
• Hats and sunglasses that children will actually wear are to hand¹

Scotland's NHS Inform summer health campaign gives the same core instruction: put on sunscreen with at least SPF 30³⁰, and the South Western Ambulance Service NHS Foundation Trust adds simply: wear sunscreen of at least SPF 30 and reapply regularly³¹. The message does not vary between the four nations, which makes it easy to hold onto: factor 30 or more, four or five stars, twice as much as you think, and shade in the middle of the day.