Sun poisoning feels like a sunburn that has crossed a line. Your skin is red and painful, but you’re also experiencing symptoms that have nothing to do with your skin: nausea, chills, a pounding headache, or dizziness. If your sunburn comes with these whole-body symptoms, you’re likely dealing with sun poisoning rather than an ordinary burn.
Sun poisoning isn’t a formal medical diagnosis. It’s the common term for a severe sunburn that triggers systemic reactions, meaning your body is responding to the UV damage internally, not just at the skin’s surface.
What Sun Poisoning Looks Like on Your Skin
A regular sunburn turns your skin red, warm, and tender. Sun poisoning does all of that, but it also produces blisters. These fluid-filled blisters indicate a second-degree burn, where UV radiation has damaged deeper layers of skin. The redness is typically more intense and widespread, and the pain is noticeably worse than a standard “forgot to reapply sunscreen” burn.
Swelling tends to be more pronounced, and the affected skin may look almost shiny or taut. If you press on it, the pain is sharp rather than just uncomfortable. The blistering can appear within a few hours of sun exposure or develop overnight, sometimes catching people off guard the morning after a long day outdoors.
The Symptoms That Go Beyond Your Skin
The defining feature of sun poisoning is that it makes you feel sick, not just sore. Common symptoms include:
- Fever and chills: You may find yourself shivering under blankets despite having a burn that radiates heat.
- Headache: Often persistent and worsened by dehydration.
- Nausea and vomiting: Your body’s inflammatory response to severe UV damage can trigger gastrointestinal symptoms.
- Dizziness or lightheadedness: Sometimes progressing to confusion or faintness.
- Rapid heartbeat: Often a sign that dehydration is setting in.
- Extreme fatigue: Far beyond the tiredness you’d expect after a day in the sun.
Much of this comes down to dehydration. Severe sunburn pulls fluid toward the damaged skin and increases fluid loss, which is why you might feel intensely thirsty alongside everything else. If you’re experiencing nausea, dizziness, or general illness after heavy sun exposure, dehydration is a major driver.
How Quickly Symptoms Appear
Skin redness from a sunburn typically starts within two to six hours after UV exposure and peaks around 24 hours. Sun poisoning follows a similar skin timeline, but the systemic symptoms (chills, nausea, headache) can hit before the burn fully develops. You might start feeling off while you’re still outdoors or within the first few hours after coming inside. The worst of it usually hits within 12 to 24 hours.
Recovery takes longer than a typical sunburn. While a mild sunburn fades within three to five days, sun poisoning can leave you feeling unwell for several days, and the skin itself may take a week or more to heal, especially if blisters are involved.
Conditions That Mimic Sun Poisoning
Not every painful reaction to sunlight is sun poisoning. Two other conditions can look similar but behave differently.
Polymorphous Light Eruption
This is a rash triggered by sun exposure that produces dense clusters of small bumps, raised rough patches, and intense itching or burning. It typically shows up on areas that were covered during winter but exposed in summer, like the upper chest, front of the neck, and arms. The rash appears 30 minutes to several hours after sun exposure and usually resolves within 10 days without scarring. Unlike sun poisoning, it’s an immune reaction to UV light rather than a burn, and it rarely causes fever or nausea.
Solar Urticaria
This is a rare condition where sunlight triggers hives: flat red marks or raised red and white welts that appear within minutes of exposure. The rash itches, stings, and burns, but it typically fades within a few hours (almost always within 24 hours). The speed of onset is the key distinguisher. If you develop welts within minutes of stepping into sunlight and they disappear quickly after you go indoors, that pattern points to solar urticaria rather than sun poisoning.
Why Some People Burn More Severely
Fair skin, light eyes, and red or blonde hair increase your baseline risk, but medications are a frequently overlooked factor. A wide range of common drugs increase your skin’s sensitivity to UV light, making severe burns more likely even with moderate sun exposure. These include certain antibiotics, cholesterol-lowering statins, blood pressure medications (particularly water pills), ibuprofen and naproxen, oral contraceptives, acne medications like isotretinoin, and even some antihistamines. Alpha-hydroxy acids found in skincare products can also increase sun sensitivity.
If you’ve started a new medication and then experienced a surprisingly severe sunburn, the drug may be amplifying your UV sensitivity. Check the label or ask your pharmacist whether sun sensitivity is a known side effect.
When Sun Poisoning Needs Medical Attention
Most mild-to-moderate sun poisoning improves with rest, fluids, cool compresses, and time. But certain symptoms signal that your body needs more help than home care can provide. The American College of Emergency Physicians recommends seeking immediate care if a severe, blistering sunburn is accompanied by fever or chills, nausea or vomiting, or confusion.
You should also watch your blisters carefully as they heal. Blisters that fill with pus or develop red streaks radiating outward are signs of a secondary skin infection, which needs treatment to prevent it from spreading.
Dehydration is the most common complication. If you can’t keep fluids down because of nausea, or if you notice dark urine, a dry mouth, or dizziness when standing, you may need intravenous fluids to recover safely.
What Helps While You Recover
Stay out of the sun entirely until your skin has healed. Even indirect sunlight through windows can worsen inflammation on damaged skin. Drink water steadily throughout the day, more than you think you need, since your body is losing extra fluid through the burned skin.
Cool (not cold) baths or damp cloths on the burned areas can ease pain and reduce heat. Avoid popping blisters, as intact blisters protect the raw skin underneath from infection. Loose, soft clothing over burned areas prevents friction that can tear blisters or intensify pain. Over-the-counter pain relief can help with the headache and skin discomfort, though if you’re also dealing with nausea, taking medication on an empty stomach may make things worse.
Peeling is normal as the skin heals, but the new skin underneath is especially vulnerable to UV damage. Plan on being extra careful with sun protection for several weeks after recovery.