(NBC NEWS) -- "The concern is some of the chemicals that are in the sunscreen could cause problems," explains pediatrician Dr. Jim Fortenberry.
Dr. Fortenberry is the Chief of Critical Care Medicine at Children's Healthcare of Atlanta.
He says these little ones should stay in the shade and wear sun-protective clothing like a broad rimmed hat.
Also, watch out for dehydration.
"Thirst is not a great mechanism to prevent heat injury, so encourage your child to drink a lot before they go outside and get hot," Dr. Fortenberry cautions.
He advises parents that lifeguards should not be the only safeguards in the pool.
Swimming safety experts say parents aren't really watching their kids unless they're looking right at them. That's because a swimmer in trouble doesn't have the energy to call out for help to get your attention. They're already using all their strength to keep their head above water.
Finally, babies and toddlers who are potty training should wear swim diapers.
A recent study found more than half of community pools have traces of fecal matter in the water.