But not without some guidelines.
"We have rules," Tunis said. "They don't go in the pool without one of their parents on the deck."
According to pediatric emergency physician Dr. Elizabeth Murray, the key is water safety in general. A recent blog went viral last week, after a mother wrote about something she called "secondary drowning." The blogger describes when her toddler swallowed water, he didn't show any medical problems until hours later.
"That can set off a chain reaction in their lungs," Murray said. "Medically, we call it 'pnuemonitis.' basically that's just a fancy term for irritation of the lungs. What that does is make your lungs not work correctly."
A child may come across tired or their personality may change, but Murray emphasizes how rare cases like that can be.
"You don't necessarily need to be more worried about this one phenomenon," she said. "Just, in general, keep your kids safe, and watch them closely."
In fact, Murray suggests parents stay within arm's reach, and where your pool is concerned, the rule of fours apply:
"What we mean by that is any pool should have a fence at least 4 feet tall," she said, "and the slats between the fence should be no more than four inches of space underneath the fence."
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