If your baby gets a sunburn and is under a year old, call her doctor, even if it appears mild. A baby's skin is much more sensitive to sunlight, and even a mild sunburn can be more serious than it appears. Your doctor may give you treatment advice over the phone, or ask to bring her in for an evaluation.
If your baby is over a year old and the burn appears mild, you can treat it at home. A mild burn causes warm, red, and painful skin, and the first 24 hours are usually the most painful. Apply cold compresses to the affected areas, or bathe your child in cool water. The AAP approves of using acetaminophen for pain relief — just be sure to follow the appropriate dosage directions for your child's height and weight. Make sure your child drinks plenty of fluids so she stays hydrated.
If your child's burn causes blisters, fever, chills, headache, or any general feelings of illness, call her doctor.