A mild sunburn looks like pink or red skin that feels hot and tight to the touch. A more severe sunburn turns intensely red, may develop blisters, and can appear wet or shiny. The exact appearance depends on the severity of the burn and your natural skin tone, but the progression from pink warmth to deep redness to blistering follows a predictable pattern.
Mild Sunburn: First-Degree Burns
Most sunburns fall into this category. On lighter skin, you’ll see a clear pink-to-red color change across the areas that were exposed to the sun. The redness often has a sharp boundary line where clothing or sunscreen protected the skin, which is one of the easiest ways to confirm you’re looking at a sunburn rather than another type of rash. The skin feels warm or hot when you press it, and it may look slightly puffy compared to the surrounding area.
On medium and darker skin tones, the redness can be harder to spot visually. Instead, a sunburn may look slightly darker than usual or have a faintly ashy appearance. The heat and tenderness are often more reliable indicators than color change alone. Pressing the skin briefly with a finger and watching it blanch (turn lighter, then flush back) can help confirm the burn.
Mild sunburns don’t blister. The skin stays intact, feels tight, and is painful to touch. After several days, the damaged top layer begins to peel off in thin, papery sheets. This peeling is your body shedding cells too damaged to repair.
Severe Sunburn: Blisters and Swelling
A second-degree sunburn looks noticeably different from a mild one. The skin turns a deep, intense red and may develop fluid-filled blisters ranging from tiny dots to larger bubbles. The surface can look wet or glossy, almost as if the skin is weeping. You may also notice patches of white discoloration within the burned area, which signals deeper damage to the skin layers.
Swelling is more pronounced with severe burns and can spread over a large area. Faces, shoulders, and the tops of feet tend to swell the most because the skin there is thinner. The blisters are fragile and may break open on their own, leaving raw, tender patches underneath. If this happens, the exposed skin is vulnerable to infection.
Severe sunburns can also cause symptoms beyond the skin itself. Headache, nausea, vomiting, fever, and chills all indicate that the burn has triggered a systemic inflammatory response, sometimes called sun poisoning. These whole-body symptoms typically accompany widespread blistering burns and signal that the damage goes well beyond cosmetic redness.
How Sunburn Changes Over Time
Sunburn doesn’t show up immediately. You can feel fine at the beach and look progressively worse hours later. Redness typically begins within a few hours of UV exposure and continues deepening for up to 24 hours, which is why a burn that looks mild in the evening can look much worse the next morning. Pain usually peaks during that same window.
A mild burn heals in roughly 3 to 5 days. Peeling starts around the tail end of that timeline and can last up to a week, though small flakes of skin may continue shedding for days or even weeks after the initial peel. The new skin underneath is thinner and more sensitive to sun exposure than the skin it replaced.
Blistering burns take longer. The blisters themselves may persist for several days before flattening or breaking, and the raw skin beneath needs additional time to heal. Redness and tenderness from a severe burn can linger for two weeks or more.
Sunburn vs. Heat Rash vs. Sun Rash
Red skin after time outdoors isn’t always a sunburn. Two common lookalikes are heat rash and sun rash, and each has distinct visual features.
- Sunburn produces broad, even redness across sun-exposed areas with clear tan lines where skin was covered. It feels hot and tight. No raised bumps in mild cases.
- Heat rash shows up as small bumps or tiny blisters in areas where skin folds or clothing creates friction: armpits, elbow creases, the groin. It feels prickly or itchy rather than hot and tender. It doesn’t require sun exposure at all, just heat and sweat.
- Sun rash appears on sun-exposed skin but looks like clusters of small, itchy red bumps rather than a uniform flush. It has a burning, itchy quality and tends to affect people with specific sun sensitivity.
The simplest distinction: sunburn is a flat, even color change with sharp clothing lines. Rashes produce bumps, and their location or pattern tells you which type you’re dealing with.
Signs a Sunburn Needs Medical Attention
Most sunburns heal on their own with cool compresses, moisturizer, and time. But certain visual and physical signs indicate the burn has crossed into territory that benefits from medical care: blisters covering a large area, white patches within the burn, skin that looks wet or raw, and swelling that seems disproportionate to the redness. Fever, chills, severe headache, or vomiting alongside a blistering burn suggest sun poisoning and warrant a call to your doctor or a visit to urgent care.