Reviewed by The Wellness Team. Last reviewed October 2026.
Sunburn is not just sore skin. It is a radiation burn, and the damage is done before the skin even turns red. Most sunburn heals at home within a week, but the right first aid makes a real difference to how it feels and how it heals, and some burns genuinely need a doctor. This guide covers what works, what to avoid, and the warning signs to take seriously.
What sunburn actually does to your skin
Ultraviolet light injures the DNA in skin cells. The redness, heat and pain that follow are your body's inflammatory response to that injury, which is why sunburn typically appears two to six hours after exposure and peaks around a day later. Blistering means the burn is deeper.
Every blistering sunburn raises the long-term risk of skin cancer, and burns in childhood matter most. Treating a burn well does not undo the DNA damage, which is why prevention gets its own section below.
How to treat a fresh burn
Get out of the sun as soon as you notice the skin going pink, because a burn keeps developing for hours. Cool the skin with a lukewarm or cool shower, or a cool damp cloth held on the area for ten to fifteen minutes several times a day. Afterwards, apply a plain moisturiser or aloe vera gel while the skin is still slightly damp, and repeat often.
Drink plenty of water, because a significant burn pulls fluid towards the skin. Ibuprofen or paracetamol, taken as directed on the packet, helps with pain and inflammation, and works best if started early. Wear loose, soft clothing over the area and stay out of the sun while it heals.
If blisters form, do not pop or peel them. The blister roof is a sterile dressing, and breaking it opens the door to infection.
What not to put on sunburn
Butter, cooking oils and toothpaste belong in the kitchen, not on a burn. They trap heat and irritate damaged skin. Be cautious with sprays and creams containing benzocaine or lidocaine too: they numb briefly but often irritate or cause allergic reactions on burned skin. Plain moisturiser, aloe vera and cool water beat every folk remedy.
When sunburn needs a doctor
Most sunburn is miserable but manageable at home. Seek medical advice if blisters cover a large area, if you develop a fever, chills, dizziness, headache or nausea, or if the pain is severe despite the measures above. These can signal a deeper burn or heat illness, and both deserve proper assessment.
Babies and young children with anything more than mild redness should be seen. You should also get advice if the burn later shows signs of infection: spreading redness, increasing pain, pus, or feeling generally unwell. A GP can assess the depth of the burn, advise on dressings and pain relief, and treat infection where it develops.
Prevention that actually works
Shade is the most reliable protection, especially between 11am and 3pm from spring to autumn. Beyond that, use a sunscreen rated SPF 30 or higher with a high UVA star rating, apply it generously twenty to thirty minutes before going out, and reapply every two hours and straight after swimming or heavy sweating. Most people apply less than half the amount needed for the labelled protection. A hat and sunglasses protect the scalp and eyes, which sunscreen cannot.
Remember that most ultraviolet light passes through light cloud, so a grey day is no guarantee, and water, sand and snow all reflect extra ultraviolet onto the skin.
Questions people ask
How long does sunburn take to heal?
Redness and tenderness usually settle over three to five days, with peeling around the one-week mark. A severe, blistering burn can take two weeks or more, and the skin underneath stays sensitive for longer.
Can you get sunburned through cloud?
Yes. Light cloud blocks only a fraction of ultraviolet light, and it is easy to burn on a bright but overcast day, particularly near water or at altitude.
Is sunburn more serious for children?
Yes. Children's skin is more vulnerable, and blistering sunburns in childhood are linked to a higher risk of melanoma later in life. Children with significant burns should be seen by a doctor.
When can I go back in the sun?
Not until the skin has fully healed: no redness, no peeling, no tenderness. Burned skin that is re-exposed burns again faster and more deeply.
If a burn is severe, blistering widely, or you are worried about infection or heat illness, a GP can assess it and advise on the right treatment. Message us on WhatsApp, call 020 3951 3429, or email team@thewellnesslondon.com. A telephone appointment is £59, a video consultation is £150, and an in-person visit at our London clinic is £220. Same-day appointments are often available.