Sunburn is red, painful skin that feels hot to the touch. It usually appears within a few hours after too much exposure to ultraviolet (UV) light from sunshine or artificial sources, such as sunlamps. Home remedies can usually provide sunburn relief, but sunburn may take days to fade.

Intense, repeated UV light exposure that results in sunburn increases the risk of other skin damage, such as dark spots, rough spots, and dry or wrinkled skin. It also raises the risk of skin cancers such as melanoma.

You can prevent sunburn and related conditions by protecting your skin. This is especially important when you’re outdoors, even on cool or cloudy days.

Sunburn signs and symptoms can include:

• Changes in skin tone, such as pinkness or redness
• Skin that feels warm or hot to the touch
• Pain and tenderness
• Swelling
• Small fluid-filled blisters, which may break
• Headache, fever, nausea and fatigue, if the sunburn is severe
• Eyes that feel painful or gritty

Any exposed part of your body — including your earlobes, scalp and lips — can burn. Even covered areas can burn if, for example, your clothing has a loose weave that allows ultraviolet (UV) light through. Your eyes, which are extremely sensitive to the sun’s UV light, also can burn.

Sunburn signs and symptoms usually appear within a few hours after sun exposure. But it may take a day or more to know how severe the sunburn is.

Within a few days, your body may start to heal itself by peeling the damaged skin’s top layer. After peeling, your skin may temporarily have an irregular color and pattern. A bad sunburn may take several days to heal.

When to see a doctor

See your doctor if the sunburn:

• Is blistering and covers a large portion of your body
• Develops blisters on the face, hands or genitals
• Is causing severe swelling
• Shows signs of infection, such as pain, pus or red streaks leading away from an open blister
• Doesn’t improve within a few days

Seek emergency medical care if you are sunburned and experience

• A fever over 103 degrees
• Confusion
• Fainting
• Dehydration

Sunburn is caused by too much exposure to ultraviolet (UV) light. UV light may be from sunlight or artificial sources, such as sunlamps and tanning beds.

Melanin is the dark pigment in the skin’s outer layer that gives skin its normal color. When you’re exposed to UV light, your body protects itself by producing melanin faster. The extra melanin creates tan. A suntan is the body’s way of blocking UV rays to prevent sunburn. But the protection only goes so far. Too much UV light causes skin to burn.

You can get sunburn on cool or cloudy days. Snow, sand, water and other surfaces can reflect UV rays that cause the skin to burn too.

Risk factors for sunburn include:

• Having light skin, blue eyes, and red or blond hair
• Living or vacationing somewhere sunny, warm or at high altitude
• Working outdoors
• Swimming or spraying your skin with water, as wet skin tends to burn more than does dry skin
• Mixing outdoor recreation and drinking alcohol
• Regularly exposing unprotected skin to UV light from sunlight or artificial sources, such as tanning beds
• Taking a drug that makes you more likely to burn (photosensitizing medications)

Intense, repeated sun exposure that results in sunburn increases your risk of other skin damage and certain diseases. These include premature aging of skin (photoaging), precancerous skin lesions and skin cancer.

Premature aging of your skin

Sun exposure and repeated sunburns accelerate the skin’s aging process, making you look older than you are. Skin changes caused by UV light are called photoaging. The results of photoaging include:

• Weakening of connective tissues, which reduces the skin’s strength and elasticity
• Deep wrinkles
• Dry, rough skin
• Fine red veins on your cheeks, nose and ears
• Freckles, mostly on your face and shoulders
• Dark or discolored spots (macules) on your face, back of hands, arms, chest and upper back — also called solar lentigines (len-TIJ-ih-neze)

Precancerous skin lesions

Precancerous skin lesions appear as rough, scaly patches in areas that have been damaged by the sun. They’re usually found on the sun-exposed areas of the head, face, neck and hands of light-skinned people. These patches can evolve into skin cancer. They’re also called actinic keratoses (ak-TIN-ik ker-uh-TOE-seez) and solar keratoses.

Skin cancer

Excessive sun exposure, even without sunburn, increases your risk of skin cancer, such as melanoma. It can damage the DNA of skin cells. Sunburns in childhood and adolescence may increase your risk of developing melanoma later in life.

Skin cancer develops mainly on areas of the body most exposed to sunlight, including the scalp, face, lips, ears, neck, chest, arms, hands, legs and back.

Some types of skin cancer appear as a small growth or a sore that bleeds easily, crusts over, heals and then reopens. With melanoma, an existing mole may change, or a new, suspicious-looking mole may develop. A type of melanoma called lentigo maligna develops in areas of long-term sun exposure. It starts as a tan flat spot that slowly darkens and enlarges.

See your doctor if you notice a new skin growth, a bothersome change in your skin, a change in the appearance or texture of a mole, or a sore that doesn’t heal.

Eye damage

The sun can also burn your eyes. Too much UV light damages the retina, lens or cornea. Sun damage to the lens can lead to clouding of the lens (cataracts). Sunburned eyes may feel painful or gritty. Sunburn of the cornea is also called snow blindness.

Use these methods to prevent sunburn, even on cool, cloudy or hazy days. And be extra careful around water, snow and sand because they reflect the sun’s rays. In addition, UV light is more intense at high altitudes.

• Avoid sun exposure between 10 a.m. and 4 p.m. The sun’s rays are strongest during these hours, so try to schedule outdoor activities for other times. If you can’t do that, limit the time you’re in the sun. Seek shade when possible.
• Avoid sun tanning and tanning beds. Getting a base tan doesn’t decrease your risk of sunburn.
• Cover up. When outside, wear a wide-brimmed hat and clothing that covers you, including your arms and legs. Dark colors offer more protection, as do tightly woven fabrics. Consider using outdoor gear specially designed to provide sun protection. Check the label for its ultraviolet protection factor (UPF), which indicates how well a fabric blocks sunlight. The higher the UPF number, the better.

• Use sunscreen frequently and generously. Apply water-resistant sunscreen and lip balm with an SPF of 30 or greater and broad-spectrum protection against ultraviolet A (UVA) and ultraviolet B (UVB) rays.

  About 15 to 30 minutes before going outdoors, apply sunscreen generously on skin that won’t be protected by clothing. Put on more sunscreen every 2 hours and after swimming or sweating. If you’re also using insect repellent, apply the sunscreen first. The American Academy of Dermatology does not recommend products that combine an insect repellent with a sunscreen.

  The Food and Drug Administration requires all sunscreen to retain its original strength for at least three years. Check the sunscreen labels for directions on storing and expiration dates. Throw away sunscreen if it’s expired or more than three years old.

• Protect babies and toddlers. The American Academy of Pediatrics recommends using other forms of sun protection, such as shade or clothing, for babies under 6 months. When that’s not possible, apply sunscreen with at least 15 SPF to the face and back of the hands. The American Academy of Dermatology recommends not using sunscreen on children under 6 months. Keep them cool, hydrated and out of direct sunlight.

  If sun protective clothing and shade aren’t available, consider using sunscreen on babies and toddlers. Use products that contain physical blockers (titanium oxide, zinc oxide), as they may cause less skin irritation.

• Wear sunglasses when outdoors. Choose sunglasses with UVA and UVB protection. Check the UV rating on the label when buying new glasses. Darker lenses are not necessarily better at blocking UV rays. It also helps to wear sunglasses that fit close to your face or have wraparound frames.
• Be aware of sun-sensitizing medications. Some common prescription and over-the-counter drugs, including antibiotics, retinoids and ibuprofen, can make skin more sensitive to sunlight. Talk with your pharmacist or doctor about the side effects of medications you take.

Your doctor is likely to conduct a physical exam and ask questions about your symptoms, UV exposure and sunburn history.

If you develop a sunburn or skin reaction after minor exposures to sunlight, your doctor might recommend a test where small areas of skin are exposed to measured amounts of UVA and UVB light to try to mimic the problem (phototesting). If your skin reacts to the UV light, you’re considered sensitive to sunlight (photosensitive).

If you’ve been sunburned, it may take two days for the severity of your burn to become evident and several more days for your skin to begin to heal.

Sunburn treatment doesn’t heal your skin, but it can reduce pain, swelling and discomfort. If care at home doesn’t help or your sunburn is very severe, your doctor might offer additional treatments or admit you to a hospital.

Once sunburn occurs, you can’t do much to limit damage to your skin. But the following tips might reduce your pain, swelling and discomfort:

• Take a pain reliever. For pain relief take an over-the-counter pain reliever such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) as soon as possible after sun exposure. Some pain relievers are gels that you apply to your skin.
• Cool the skin. Apply to the affected skin a clean towel dampened with cool tap water. Or take a cool bath with added baking soda — about 2 ounces (60 grams) per tub. Cool the skin several times a day.
• Apply a moisturizer, lotion or gel. An aloe vera lotion or gel or calamine lotion might be soothing.
• Drink water to prevent dehydration.
• Don’t break intact blisters. If a blister does break, clean it with mild soap and water. Then apply an antibiotic ointment to the wound and cover it with a nonstick bandage.
• Treat peeling skin gently. Within a few days, the affected area may begin to peel. This is your body’s way of getting rid of the top layer of damaged skin. While your skin is peeling, continue to moisturize.
• Take an anti-itch drug. An oral antihistamine such as diphenhydramine might help relieve itching as the skin begins to peel and heal underneath.
• Apply a corticosteroid cream. For mild to moderate sunburn, apply over-the-counter corticosteroid cream to the affected area.
• Protect your sunburn from further sun exposure. While your skin heals, stay out of the sun, or protect your skin if you do go out.

• Avoid applying ‘-caine’ products, such as benzocaine. Such creams can irritate the skin or cause an allergic reaction. Benzocaine has been linked to a rare but potentially deadly condition that decreases the amount of oxygen that the blood can carry (methemoglobinemia).

  Don’t use benzocaine in children younger than age 2 without supervision from a health care professional. If you’re an adult, never use more than the recommended dose and consider talking with your doctor before using it.

Most sunburns heal fine on their own. Consider seeking treatment for severe or repeated sunburn. You’re likely to first see your primary care doctor. Before you go to your appointment, list the medications you’re taking — including vitamins, herbs and over-the-counter drugs. Some drugs increase your sensitivity to UV light.

Questions to ask your doctor about sunburn include:

• Can I use over-the-counter medications to treat the condition, or do I need a prescription?
• How soon after I begin treatment can I expect improvement?
• What skin care routines do you recommend while the sunburn heals?
• What suspicious changes in my skin might I watch for?

If your sunburn is severe or your doctor notices any skin abnormalities, you might be referred to a doctor who specializes in skin diseases (dermatologist) for further evaluation.