Sunburn: Causes, Symptoms, Treatment, and Prevention | Easy Guide

Sunburn treatment starts with cooling the skin, staying hydrated, and using OTC pain relievers — but severe cases with blisters, high fever, or signs of dehydration need a doctor's attention. Sunburn is caused by overexposure to the sun's ultraviolet (UV) rays and can range from mild redness to second-degree burns. It also raises your long-term risk of skin cancer. This guide covers causes, symptoms, treatment by severity, and how to prevent sunburn.

What Causes Sunburn?

Sunburn is caused by exposure to the sun's UV rays, specifically UVA and UVB rays. These rays penetrate the skin and can cause damage to the DNA in skin cells. The amount of time it takes to get a sunburn depends on your skin type, the sun's intensity, and how long you're exposed to the sun.

Sunburn Symptoms

The most common symptoms of sunburn include:

• Red, painful skin

• Swelling

• Blisters (in severe cases)

• Flu-like symptoms (fever, chills, nausea, headache, weakness)

• Peeling and itching skin (a few days after the burn)

Mild vs. Moderate vs. Severe Sunburn: How to Tell the Difference

Not all sunburns are the same. Knowing how severe yours is helps you choose the right treatment — and know when to get help.

Mild sunburn is the most common type. Skin looks pink or red, feels warm or tender, and may be slightly swollen. Symptoms typically appear within a few hours of sun exposure and peak around 24–36 hours. Mild sunburns usually heal on their own within 3–5 days, with peeling starting a few days after the burn.

Moderate sunburn covers a larger area of the body or produces more intense redness, significant pain, and swelling. You may feel tired, headachy, or slightly feverish. Skin can feel hot to the touch even in areas not directly burned. Moderate sunburns take 5–7 days to heal and benefit from consistent at-home care: cool compresses, aloe vera gel, ibuprofen, and extra fluids.

Severe sunburn — sometimes called sun poisoning — involves second-degree burns, where blisters form on the skin. This level of burn damages deeper layers of skin and requires careful management. Do not pop blisters; they protect the skin from infection. Alongside blisters, severe sunburn can cause:

• High fever (above 103°F / 39.4°C)

• Chills, nausea, or vomiting

• Rapid pulse or rapid breathing

• Dizziness or confusion

• Extreme pain over a large body surface area

These symptoms can indicate heat exhaustion, dehydration, or an infection risk — all of which need prompt medical evaluation. Children, older adults, and people with light skin or certain medical conditions are at higher risk for severe reactions.

When to see a doctor: Seek care if you have blisters over a large area, a fever above 103°F, signs of dehydration, or if symptoms don't improve after a few days of home treatment. Our AI doctor can evaluate your sunburn severity, walk through your symptoms, and help you decide if an in-person visit is the right next step — without waiting on hold.

Sunburn Treatment

If you get a sunburn, there are several things you can do to find relief:

• Apply cold compresses or take a cool bath to soothe the skin

• Use creams or gels containing menthol, camphor, or aloe vera

• Take over-the-counter pain relievers like ibuprofen or naproxen

• Stay hydrated by drinking plenty of water and other fluids

• Avoid further sun exposure until the burn heals

If you have a severe sunburn with blisters covering a large area of your body, a high fever (above 103°F), confusion, or signs of dehydration (dizziness, rapid heartbeat, no urination), seek medical care right away. Our AI doctor can help you assess your symptoms and decide if urgent care or an ER visit is needed.

Preventing Sunburn

The best way to deal with sunburn is to prevent it from happening in the first place. Here are some tips for protecting your skin from the sun:

• Avoid sun exposure between 10 a.m. and 4 p.m. when the sun's rays are strongest

• Wear protective clothing like a broad-brimmed hat, long-sleeved shirt, pants, and UV-blocking sunglasses

• Apply broad-spectrum sunscreen with an SPF of at least 30 to all exposed skin, and reapply every 2 hours or after swimming or sweating heavily

• Talk to your doctor about any medications you take that may increase your skin's sensitivity to the sun

By following these simple tips, you can enjoy time outdoors while keeping your skin safe from harmful UV rays and reducing your risk of sunburn and skin cancer. Remember, if you notice any unusual changes in your skin, such as a mole that is changing, growing, or bleeding, contact your doctor right away, as this may be a sign of skin cancer.

For more information on sun safety and skin protection, visit the CDC's sun safety page or the American Academy of Dermatology's sun protection guide.

The Bottom Line

Prevention through sunscreen, protective clothing, and avoiding peak UV hours (10am-4pm) is far more effective than treating sunburn after it occurs. If you have severe sunburn with extensive blistering, fever, or signs of heat exhaustion, Doctronic can help assess whether medical treatment is needed.