Sunburns: what you should know

What they are, how to relieve them without worsening the skin, and in what situations it is advisable to consult a doctor.

Summary in 60 seconds

• Sunburn is an acute inflammatory reaction of the skin to excessive ultraviolet radiation; UVB plays a central role in redness and pain. (Milner-2024 , WHO-2022)
• It’s not always noticeable right away: it usually appears within a few hours, worsens between 12 and 24 hours, and then the hair may peel. Milner-2024
• Red, hot, tight, and painful skin is normal; blisters indicate a more serious injury. Milner-2024 , AAD-2024
• Fever, chills, nausea, dizziness, intense thirst, or eye pain warrant medical attention. MedlinePlus-2025
• Reasonable relief begins with getting out of the sun, cooling the skin with cool water, moisturizing, and drinking more fluids . AAD-2024 , MedlinePlus-2025
• Do not break blisters or use topical anesthetics such as benzocaine or lidocaine. AAD-2024 , MedlinePlus-2025
• Sunscreen helps, but it’s not a substitute for shade, clothing, or limiting sun exposure. CDC-2026 , AAD-2025
• Repeated sunburns throughout life increase the risk of skin cancer. Dennis-2008 , WHO-2022

What are they?

Sunburn is an acute inflammation of the skin following excessive exposure to ultraviolet radiation. In practice, it usually behaves like a superficial burn: the skin reddens, becomes hot, painful, and may swell. Symptoms do not always appear immediately; they often begin 3 to 5 hours later, peak at 12–24 hours, and, in mild cases, improve over several days. (Milner, 2024 ; Guerra-Crane, 2023)

It’s important to remember that any skin tone can burn. Some people burn more easily, but dark skin is not immune to sun damage. (MedlinePlus-2025 , NCI-2023)

Why do they appear?

It occurs when the amount of UV radiation exceeds the skin’s natural protective capacity. This can happen in the sun, but also with tanning beds or booths. The risk increases around midday, at high altitudes, near the equator, and on surfaces that reflect radiation, such as water, sand, or snow. (WHO-2022 , MedlinePlus-2025 , NCI-2023)

Personal factors also play a role: skin that reddens easily, a history of sunburns, intense intermittent sun exposure, and certain medications or illnesses that make the skin more sensitive to the sun. Common examples include certain antibiotics, retinoids, some diuretics, and anti-inflammatory drugs. (MedlinePlus-2025 , Guerra-Crane-2023)

What do they look like and what symptoms do they cause?

The usual symptoms are redness, warmth, tenderness, pain, and a feeling of tightness. Later, peeling may appear. If the injury is more severe, blisters may develop and be accompanied by general symptoms such as fever, chills, nausea, or malaise. (Milner-2024 , MedlinePlus-2025)

A somewhat counterintuitive detail: by the time the skin is red and painful, the damage has already been done. That’s why «wait and see» is usually a bad strategy. MedlinePlus-2025

What can you do today?

Start by getting out of the sun and moving to the shade or indoors. Then, cool your skin with a cool shower, short baths, or cool, damp cloths; then apply a gentle moisturizer, ideally while your skin is still slightly damp. (AAD-2024 , MedlinePlus-2025)

If you have no medical contraindications, common pain relievers such as ibuprofen or acetaminophen can help with the pain. It’s also advisable to drink more water than usual in the following hours, as some body fluid shifts to the swollen skin. AAD-2024 , MedlinePlus-2025

If blisters appear, do not pop them. Keep the area clean, avoid friction, and protect the skin from the sun until it has fully healed. AAD-2024 , War-Crane-2023

What NOT to do?

• Do not expose yourself again “just for a little while” while the skin is still red, hot, or painful. AAD-2025 , NCI-2023
• Don’t pop blisters: you increase the risk of infection and delay healing. AAD-2024 , MedlinePlus-2025
• Do not use topical anesthetics such as benzocaine or lidocaine to “numb” the skin. MedlinePlus-2025 , War-Crane-2023
• Don’t rely solely on sunscreen to prolong sun exposure; it must be combined with shade and clothing. CDC-2026 , AAD-2024
• Do not use tanning beds as a “safer” alternative. They also emit UV radiation. NCI-2023 , Guerra-Crane-2023

When should I consult a specialist?

Consult a healthcare professional if any of these signs appear:

• fever, chills, nausea, dizziness, or feeling faint; MedlinePlus-2025
• intense thirst, very little urine, rapid breathing, or signs of dehydration; MedlinePlus-2025
• extensive or very painful blisters; MedlinePlus-2025
• eye pain or marked sensitivity to light; MedlinePlus-2025 , WHO-2022
• Sunburn in a young infant or child who is also lethargic or irritable. CDC-2026 , AAD-2025

What does a dermatologist usually do?

In a typical sunburn, the diagnosis is usually based on medical history and physical examination: when it occurred, how much sun exposure was received, whether blisters were present, what medications you are taking, and how much skin is affected. (MedlinePlus-2025 , Guerra-Crane-2023)

Further studies are considered when the appearance is inconsistent, the reaction is disproportionate to the exposure, or there is suspicion of photosensitivity or another skin condition. Guerra-Crane-2023

Frequently Asked Questions

How long does it last?

• The most bothersome phase usually occurs during the first 24–48 hours. Redness typically improves within a few days, and peeling may continue for about a week. (Milner, 2024 ; Guerra-Crane, 2023)

Does aloe vera work?

• It can relieve the burning and tightness, but it doesn’t undo the damage already done. Its role is soothing, not miraculous. AAD-2024 , War-Crane-2023

Can I still get sunburned if it’s cloudy?

• Yes. Official recommendations emphasize reapplying sunscreen even on cloudy days, and radiation can also be reflected by water, sand, or snow. AAD-2025 , NCI-2023

Does brown or dark skin not burn?

• Yes, you can get burned. The average risk may be lower, but it doesn’t disappear. MedlinePlus-2025 , NCI-2023

Does sunscreen completely prevent sunburn?

• No. No sunscreen blocks 100% of UVB radiation, and it must be reapplied. It works best when combined with shade, clothing, and sunglasses. AAD-2024 , CDC-2026

What should I do if I have blisters?

• Don’t pop them. Protect them from friction and consult a doctor if they are large, very painful, or accompanied by fever or general malaise. AAD-2024 , MedlinePlus-2025

What about babies under 6 months old?

• The priority is to avoid direct sunlight, seek shade, and wear protective clothing. If there are any questions about sun protection at that age, it’s worth consulting a pediatrician. CDC-2026 , AAD-2025

Bibliography and sources

1. World Health Organization. Ultraviolet radiation . WHO; updated June 21, 2022. Accessed March 28, 2026.
2. Centers for Disease Control and Prevention. Sun Safety Facts | Skin Cancer . CDC; updated February 10, 2026. Accessed March 28, 2026.
3. US Food and Drug Administration. Sunscreen: How to Help Protect Your Skin from the Sun. FDA; updated September 16, 2025. Accessed March 28, 2026.
4. American Academy of Dermatology. How to treat sunburn . AAD; updated May 20, 2024. Accessed March 28, 2026.
5. American Academy of Dermatology. Sunscreen FAQs . AAD. Accessed March 28, 2026.
6. American Academy of Dermatology. How to decode sunscreen labels . AAD; updated April 25, 2024. Accessed March 28, 2026.
7. MedlinePlus. Sunburn . US National Library of Medicine; reviewed June 3, 2025. Accessed March 28, 2026.
8. National Cancer Institute. Cancer Risk Factors: Sunlight . NCI; updated April 26, 2023. Accessed March 28, 2026.
9. Milner SM. Sunburn . Eplasty . 2024;24:QA17. PMID: 39233706. PMCID: PMC11374383.
10. Guerra KC, Crane JS. Sunburn . In: StatPearls [Internet] . Treasure Island (FL): StatPearls Publishing; updated October 29, 2023. Accessed March 28, 2026.
11. Dennis LK, Vanbeek MJ, Beane Freeman LE, Smith BJ, Dawson DV, Coughlin JA. Sunburns and risk of cutaneous melanoma: does age matter? A comprehensive meta-analysis . Ann Epidemiol . 2008;18(8):614-627. doi:10.1016/j.annepidem.2008.04.006.