Sun poisoning: when a sunburn becomes a medical issue

Most sunburns are uncomfortable but minor. Some, however, cross into what is informally called sun poisoning, a severe reaction that needs more attention and occasionally medical care.

The warning signs go beyond local redness and tenderness. Extensive blistering, severe swelling, fever and chills, headache, nausea, dizziness, fainting, or confusion suggest the body is reacting systemically to a significant burn and possible dehydration, and these warrant prompt medical evaluation. Such reactions are more likely with intense exposure, fair skin, certain medications that increase sun sensitivity, and in children. Some people also develop a sun-triggered itchy rash (a form of photosensitivity) that is distinct from an ordinary burn.

For a severe burn, supportive care matters: cooling, generous fluids, anti-inflammatories, and protecting the skin, with medical care for the systemic symptoms above, for very extensive burns, or for any burn in a young child that seems serious. The practical guidance is to treat ordinary sunburn at home but to recognize the red flags, fever, widespread blistering, and feeling genuinely unwell, as reasons to seek care rather than wait it out. Knowing the difference keeps a manageable burn from becoming a dangerous one.

Related reading: How your skin heals after a sunburn and Repairing long-term sun damage.