Sun poisoning feels like a sunburn that crossed a line. If your skin is blistered, you’re running a fever, or you feel nauseous and dizzy hours after being in the sun, you’re likely dealing with sun poisoning rather than an ordinary burn. A regular sunburn causes redness, pain, and hot skin that starts fading within three days. Sun poisoning lasts longer, hits harder, and affects your whole body.
Sunburn vs. Sun Poisoning
The distinction comes down to severity and whether your symptoms stay on the skin or go deeper. A mild to moderate sunburn is a surface problem: red, painful, warm skin that peaks in a day or two and resolves within about three days. Sun poisoning involves the same skin damage but triggers a systemic reaction, meaning your body responds as if it’s fighting something off.
With sun poisoning, you can expect some combination of these symptoms beyond the burn itself:
- Blistering over the burned area, sometimes in large patches
- Fever and severe chills
- Nausea or vomiting
- Headache, dizziness, or faintness
- Rapid pulse or rapid breathing
- Dehydration signs like intense thirst, dry mouth, dry eyes, or reduced urination
- Facial swelling
- Eye pain or light sensitivity
If you only have redness and tenderness without any of those whole-body symptoms, you’re probably dealing with a standard sunburn. If two or three of those symptoms show up together, that’s sun poisoning territory.
When Symptoms Appear and How Long They Last
Sunburn symptoms typically develop within a few hours of UV exposure and peak around 24 to 48 hours later. Sun poisoning follows a similar timeline for the skin symptoms, but the systemic effects (fever, nausea, chills) can build more gradually and persist well beyond the three-day window where a normal sunburn starts fading. Blistering skin takes longer to heal, and peeling can continue for a week or more.
This delayed timeline matters because you might feel fine immediately after a long day outdoors. The worst of it often doesn’t hit until the next morning, when you wake up shivering with a headache despite having a visible burn.
Sun Allergy Looks Different
“Sun poisoning” sometimes refers to a sun allergy rather than a severe burn, and the two look and feel quite different. The most common sun allergy causes itchy bumps, small raised patches, or hive-like welts on sun-exposed skin. The key difference is that itching and a bumpy texture dominate rather than the deep, even redness of a burn. These reactions tend to appear hours to days after exposure and can recur every time you get significant sun.
A rarer form, solar urticaria, produces red, itchy welts within minutes of sun exposure. These welts typically resolve on their own within one to two hours of getting out of the sun, with about 75% of cases clearing within an hour. If your skin reacts that fast and calms down that quickly, you’re likely dealing with this type of allergy rather than a burn-based reaction.
If you keep getting an unusual rash after sun exposure that doesn’t look like a typical burn, a dermatologist can run a phototesting exam. This uses a special lamp to see exactly how your skin reacts to different wavelengths of UV light. Photopatch testing can also identify whether a product you’re applying to your skin is reacting with sunlight to cause the problem. In some cases, blood tests or a skin biopsy may be needed to rule out underlying conditions like lupus, which can cause persistent sun-sensitive lesions on the face.
Medications That Raise Your Risk
Certain medications make your skin dramatically more sensitive to UV radiation, meaning you can develop sun poisoning from an amount of exposure that would normally cause only mild pinkness. According to the FDA, the major categories include common antibiotics (doxycycline, tetracycline, ciprofloxacin), certain cholesterol-lowering drugs, blood pressure medications that contain diuretics, ibuprofen and naproxen, oral contraceptives, acne medications containing retinoids like isotretinoin, and even some antihistamines like cetirizine and diphenhydramine.
Cosmetic products containing alpha-hydroxy acids (AHAs) also increase photosensitivity. If you started a new medication or skincare product and then got a surprisingly severe burn from modest sun exposure, the connection is worth investigating.
What to Do About It
For mild cases where you have some blistering but your fever is low and you can keep fluids down, home care focuses on hydration and skin protection. Drink extra water throughout the day to counteract the fluid your body is losing through damaged skin. A nonprescription 1% hydrocortisone cream applied to the affected area three times daily for three days can help reduce inflammation and pain. Cool compresses and loose clothing over the burned areas help as well. Don’t pop blisters, as the intact skin underneath is vulnerable to infection.
For more severe cases, a doctor may prescribe a stronger corticosteroid cream. Hospital admission is possible for the most serious burns, particularly when dehydration becomes difficult to manage at home or large portions of the body are blistered.
Signs You Need Immediate Help
Certain symptoms push sun poisoning into emergency territory. Get medical attention right away if you notice pale, clammy, or cool skin despite feeling overheated, since this can signal the body’s cooling system is failing. Confusion, a rapid pulse, or stopping sweating altogether are signs of heat stroke, which requires a 911 call. Signs of skin infection in the burned area, including increasing redness, swelling, warmth, or pus, also need prompt medical evaluation. The same goes for severe dehydration: if you haven’t urinated in many hours, your mouth and eyes feel dry despite drinking water, and you feel faint, you need IV fluids that home care can’t provide.