MONDAY, July 26 (HealthDay News) -- Pools offer an escape from summer heat, but parents need to take measures to protect their young children from drowning, an expert advises.

"Contrary to popular movie depictions of a drowning person who flails about and calls for help, children just sink and drown," said Joseph Torg, an adjunct professor of orthopedics and sports medicine at Temple University School of Medicine in Philadelphia.

"It happens quickly, silently, and without notice. Once submerged, children become disoriented and oblivious to the change in environment from air to liquid," Torg explained in a Temple news release.

Each year in the United States, about 500 children aged 5 and younger drown in swimming pool mishaps, according to the news release.

Torg offered the following safety tips:

• Keep an eye on children at all times, especially in crowded swimming pools.
• Children should know how to swim by the time they're 5.
• Keep pools secure using gates, fences and/or pool covers.
• Non-swimmers should be restricted to wading pools or should wear a Coast Guard-approved personal floatation device (life jacket).

People of all ages and experience should wear a life jacket when swimming in streams and rivers. Ocean swimming should be restricted to beaches with life guards, Torg said.

"With regard to pools, hot tubs, ponds, streams and rivers, the adage 'An ounce of prevention is worth a pound of cure,' is a gross understatement. With drowning, there is no cure," he said.

More information

The American Academy of Pediatrics has more about water safety and young children.