Sun poisoning is a severe sunburn that goes beyond red, tender skin and triggers whole-body symptoms like fever, chills, nausea, and headache. It isn’t a medical diagnosis on its own but rather an informal term for a sunburn intense enough to make you feel genuinely sick. While a mild sunburn might leave you uncomfortable for a day or two, sun poisoning can put you in bed with flu-like symptoms and blistering skin that takes significantly longer to heal.
How Sun Poisoning Differs From Regular Sunburn
Every sunburn involves the same basic process. Ultraviolet rays from the sun (or a tanning bed) penetrate your skin and damage the DNA inside your cells. Your body detects that damage and launches an inflammatory response, flooding the area with signals that widen blood vessels and activate pain receptors. That’s what produces the familiar redness, swelling, and tenderness.
With sun poisoning, the damage is deep and widespread enough that the reaction spills beyond the skin. The inflammatory chemicals your body releases enter your bloodstream in larger quantities, producing systemic effects: fever, chills, nausea, vomiting, headache, dizziness, and sometimes confusion. You may also lose significant fluid through damaged skin, compounding everything with dehydration. In short, a regular sunburn is a local skin injury. Sun poisoning is that same injury scaled up until your whole body responds.
Symptoms to Recognize
Sun poisoning typically starts the same way any bad sunburn does, with intensely red, painful skin that may feel hot to the touch. Within hours, though, additional symptoms appear:
- Blisters: These indicate a second-degree burn, meaning deeper layers of skin are damaged.
- Fever and chills: You may find yourself shivering under blankets despite having been overheated just hours earlier.
- Nausea and vomiting: Often driven by dehydration and the body’s systemic inflammatory response.
- Headache and dizziness: Another sign of fluid loss and widespread inflammation.
- Severe swelling: The burned area may puff up noticeably more than a typical sunburn.
- Confusion or lightheadedness: These signal significant dehydration or heat-related illness and require immediate attention.
The American College of Emergency Physicians advises seeking emergency care if a blistering sunburn is accompanied by fever, chills, nausea, vomiting, or confusion. Those symptoms together suggest your body is struggling to manage the damage on its own.
Who Is Most at Risk
Your skin’s natural pigment level is the single biggest factor. People with very fair skin, light eyes, and red or blond hair burn the fastest and most severely. On the Fitzpatrick scale, a standard classification system used in dermatology, these individuals fall into Type I (always burns, never tans) or Type II (burns easily, tans minimally). People with darker skin tones can still get sun poisoning, but the threshold of UV exposure required is considerably higher.
Certain medications also make your skin dramatically more sensitive to UV light. The FDA lists several common drug categories that increase sun sensitivity, including some antibiotics (particularly doxycycline and tetracycline), common diuretics used for blood pressure, cholesterol-lowering statins, oral contraceptives, retinoids used for acne, and even over-the-counter antihistamines and ibuprofen. If you take any of these, you can burn faster and more severely than you’d expect. Cosmetics containing alpha-hydroxy acids (AHAs) have the same effect.
Other risk factors include high altitude (thinner atmosphere filters less UV), reflective environments like water, sand, or snow, and midday sun exposure when UV intensity peaks.
How to Treat It at Home
Most cases of sun poisoning can be managed outside a hospital, though recovery is slower and more uncomfortable than a standard sunburn. Cool baths or showers are the simplest way to bring relief, and you can repeat them as often as needed. Anti-inflammatory pain relievers like ibuprofen or naproxen help with both pain and swelling, especially when taken early. If you can’t take those due to stomach issues, blood thinners, or kidney concerns, acetaminophen is a reasonable alternative for pain, though it won’t reduce inflammation.
Hydration is critical. The blistering and swelling associated with sun poisoning pull fluid and electrolytes out of your bloodstream and into your damaged skin. Drink water steadily and consider an electrolyte drink, particularly if you’ve been vomiting. Much of the nausea, dizziness, and general illness that accompany sun poisoning comes from dehydration rather than the burn itself.
A few things to avoid: topical anesthetic sprays or creams (the kind labeled “sunburn relief” with benzocaine or lidocaine) can cause allergic skin reactions on already-damaged tissue. Topical steroid creams have not been shown to provide meaningful benefit for sunburn, and on blistered skin they increase infection risk. If blisters form, leave them intact. They’re a natural barrier protecting the raw skin underneath. Popping them opens a direct path for bacteria.
Recovery Timeline
The worst pain and systemic symptoms generally peak between 24 and 48 hours after exposure. Redness and tenderness can persist for several days beyond that. Blisters may take a week or more to flatten and begin peeling. Full skin healing from a blistering sunburn often takes two to three weeks, depending on the severity and how large the burned area is. During this entire period, the affected skin is highly vulnerable to further UV damage, so keeping it covered or staying out of the sun is essential.
Peeling is a normal part of recovery. It’s your body shedding the layers of dead, UV-damaged cells. Resist the urge to pull peeling skin off, as doing so can tear into healthy tissue underneath and increase the chance of scarring or infection.
Long-Term Consequences
Sun poisoning isn’t just an unpleasant weekend. Severe sunburns carry lasting consequences for your skin. According to a World Health Organization review, UV damage divides into acute effects (the burn itself) and chronic effects that accumulate over years: premature skin aging, precancerous growths called actinic keratoses, and skin cancers including basal cell carcinoma, squamous cell carcinoma, and melanoma.
The numbers are striking. Sunburns are associated with a doubling of melanoma risk, the most dangerous form of skin cancer. Repeated burns also cause UV-signature mutations in a tumor-suppressing gene called p53, which is a key driver of squamous cell carcinoma. Beyond cancer, UV exposure accounts for an estimated 80 to 90 percent of visible skin aging, including wrinkles, loss of elasticity, and dark spots. Some people develop persistent dark patches after a severe burn that can last months to years, a sign of deep photodamage that itself is considered a risk factor for precancerous changes.
UV exposure also affects the immune system in the skin. In susceptible people, it can trigger inflammatory pathways that lead to sun-sensitivity conditions or worsen autoimmune disorders. A single episode of sun poisoning won’t guarantee any of these outcomes, but every severe burn adds measurable, cumulative risk.
Prevention That Actually Works
Sun poisoning is entirely preventable. Broad-spectrum sunscreen with SPF 30 or higher blocks the vast majority of UVB rays when applied generously and reapplied every two hours (or immediately after swimming or sweating). Most people apply only about a quarter to half the amount needed, which dramatically reduces the effective protection.
Clothing is more reliable than sunscreen for areas it covers, since it doesn’t wear off or get applied unevenly. A wide-brimmed hat and UV-blocking sunglasses protect the face and eyes, two areas especially prone to damage. Seeking shade between roughly 10 a.m. and 4 p.m., when UV intensity is highest, cuts your exposure substantially. If you’re taking any photosensitizing medication, these precautions shift from helpful to necessary.