CORONAVIRUS: WHAT DO I NEED TO KNOW? READ BELOW
The first line of defense against the sun is covering up. Stay in the shade as much as possible, and avoid sun exposure during the peak intensity hours (10 a.m. to 2 p.m.). Use a hat or visor and be aware of sun reflection off sand, water, and/or cement.
For children 6 months or older, apply sunscreen at least 30 minutes before going outside, with an SPF of at least 15. (I prefer 30.) Sunscreen must be absorbed into the skin to be most effective. It will not work as well if you wait to apply it when you get to the pool or beach. In order to not miss spots, I recommend applying sunscreen while your child is naked. Sunscreen should be reapplied every two hours or after swimming or sweating.
Practical tip: For children who complain of stinging when sunscreen gets into their eyes after sweating/swimming, try one of the "face sticks" which looks like a big lipstick. In my experience, these products stay on and don't run. (Waterbabies and Neutragena each make a face stick.)
The sensation of pain and heat will probably last for 48 hours. Treat pain early (within 6 hours of sun exposure) with acetaminophen or ibuprofen, and repeat as necessary for the first two days. An over-the-counter hydrocortisone cream (1% Cort Aid) may cut down on swelling and pain, but only if used early. This can be used 3 times per day.
Cool baths or compresses several times daily may be comforting, as well as adding baking soda to the bath water. Showers may be painful because of the force of the spray. Avoid all soaps on sunburned skin.
Replace fluids with adequate water on the first day to avoid dehydration and dizziness.
Peeling will occur on the fifth to the seventh day. Itching can be reduced with Benadryl orally, and/or 1% hydrocortisone to the itchy skin twice daily. Avoid petrolatum and ointments because they keep heat and sweat from escaping.
For complete information on sunburns, see Your Child's Health.