Sunburn blisters mean your skin has sustained a second-degree burn, and the single most important thing you can do is leave them intact. The fluid-filled bubbles act as a natural bandage, protecting the damaged skin underneath while it heals. Most sunburn blisters resolve on their own within one to two weeks, but how you care for them during that window makes a real difference in how quickly you heal and whether you develop an infection.
Why Blisters Form After a Sunburn
A sunburn that blisters has gone deeper than ordinary redness. Ultraviolet radiation has damaged not just the outer layer of skin (the epidermis) but also the second layer (the dermis). That cell damage triggers your immune system to flood the area with fluid and inflammatory compounds, which is what creates the swelling and the blisters themselves. The fluid inside is mostly plasma, and it cushions the raw tissue beneath while new skin cells grow.
Immediate Steps to Take
Get out of the sun completely and stay out until your skin has healed. Even indirect UV exposure through windows can irritate blistered skin further.
Cool the area with lukewarm or cool (not cold) water. You can drape a damp cloth over the blisters or take a cool shower, but avoid ice or ice packs directly on the skin. Extreme cold restricts blood flow to tissue that already needs repair, and the pressure can rupture blisters.
Take an over-the-counter anti-inflammatory pain reliever like ibuprofen as soon as possible after the burn. It reduces both pain and the inflammatory response driving the swelling. Acetaminophen helps with pain but won’t do as much for inflammation. For mild to moderate blistering, applying a 1% hydrocortisone cream to the area three times a day for up to three days can further calm swelling and itching.
Drink extra water. Sunburns pull fluid toward the skin’s surface, and blistering burns increase that fluid loss. You may not feel especially thirsty, but dehydration slows healing and can make you feel worse overall.
Don’t Pop the Blisters
This is the rule most people break, and it’s the one that matters most. The intact blister roof is a sterile barrier. Once it’s gone, the raw dermis underneath is exposed to bacteria, and infection becomes a real risk. Resist the urge to peel, puncture, or drain them, even if they’re tight and uncomfortable. Wear loose, soft clothing over blistered areas to minimize friction.
If a blister breaks on its own, don’t peel away the remaining skin. Gently wash the area with mild soap and water, apply a thin layer of petroleum jelly, and cover it with a non-stick gauze bandage. Change the bandage daily or whenever it gets wet or dirty. The petroleum jelly keeps the wound moist, which speeds new skin growth and reduces scarring.
What to Expect as Blisters Heal
Blisters typically appear several hours to a day after the sun exposure that caused them. Over the next few days, the fluid inside will gradually reabsorb on its own. The blister roof will flatten and eventually peel away, revealing pink, tender new skin underneath.
For most people, the full cycle from blister formation to peeling takes about one to two weeks. Severe blistering, especially over large areas, can take several weeks to fully resolve. The new skin that emerges will be more sensitive to UV light for weeks or even months, so protect it carefully with clothing or broad-spectrum sunscreen once it’s no longer raw.
Keeping Blistered Skin Comfortable
Pure aloe vera gel (without added fragrance or alcohol) can soothe intact blistered skin. Apply it gently without rubbing. Moisturizers that contain ceramides or hyaluronic acid also help once the blisters have flattened and the skin begins to peel, but avoid anything with fragrance, retinoids, or exfoliating acids until healing is complete.
Avoid petroleum jelly, heavy ointments, or butter on intact blisters. These trap heat against the skin and can make the burn feel worse. Save petroleum jelly for broken blisters that need a moisture barrier over the open wound. Similarly, avoid numbing sprays containing benzocaine, which can irritate burned skin or cause allergic reactions.
Sleep in breathable, loose fabrics. If blisters are on your back or shoulders, a clean cotton t-shirt keeps bedding from sticking to the skin overnight.
Signs of Infection to Watch For
Most sunburn blisters heal without complications, but infection is the main risk, especially if blisters have broken open. Watch for these warning signs:
- Pus or cloudy drainage from a blister (clear fluid is normal; yellow, green, or foul-smelling fluid is not)
- Red streaks radiating outward from the blister
- Increasing pain after the first two or three days, rather than gradual improvement
- Warmth or swelling that gets worse instead of better
- Fever developing days after the initial burn
Any of these signs warrant a visit to a healthcare provider, since infected burns can worsen quickly and may need prescription treatment.
When Blistering Sunburn Needs Medical Attention
Some blistering sunburns are serious enough to need professional care right away, even without signs of infection. Seek medical attention if blisters cover a large portion of your body, roughly 20% or more of your skin surface in adults (think: your entire back plus both arms). For children under 10 and adults over 50, that threshold drops to about 10% of body surface.
Blistering on the face, hands, feet, or genitals also warrants a medical visit regardless of size, because these areas are more vulnerable to scarring and complications. The same goes for sunburn blisters accompanied by high fever, chills, nausea, confusion, or feeling faint, all of which can signal sun poisoning or severe dehydration that needs more than home care.