On a hot summer day, few things are as satisfying as a dip in the pool. But whether in-ground or above ground, that oasis is a potential danger, particularly for small children, and it demands your constant vigilance.

Some 200 children a year die in swimming pools each summer in the United States, the majority of whom are under 5, according to the Consumer Product Safety Commission (CPSC).

"Unlike in the movies there are no screams for help," says UL’s consumer safety director John Drengenberg. "It's called, sadly, the 'silent death,'" Drengenberg says.

The Consumer Product Safety Commission (CPSC) notes drowning is the leading cause of unintentional death in children ages 1 through 4, and that drownings often occur when there is even a short lapse in adult supervision.

Safety experts urge people with pools to teach their kids water safety and put them in swimming lessons at a young age. But even if your child is a good swimmer, it’s up to you to understand the dangers of a pool and take the necessary steps to minimize them.

Related: Grill Safety: Read This Before Your Next BBQ

Keeping the pool area safe and secure

Safety starts with the pool itself. Pools need to be fenced, Drengenberg says. While the rules for pool fencing can vary by municipality, he says the general rule is the fence should be at least four feet high.

The entrance to the pool area should have self-closing, self-latching gates, according to the CPSC. They're intended to prevent toddlers from wandering into the pool area. Chairs should be kept away from the fence to prevent children from having an easy way to climb over, Drengenberg notes,

If there is direct access to the pool through the home, such as through a sliding door to a deck, that access point should be locked and secured with a child safety device — typically a latch placed high on the door or a gadget that limits the movement of the door — to ensure a small child can't simply flip the lock and slide open the door. The CPSC suggests an alarm that makes a sound when the door is opened.

Other ways to keep kids out of the pool when you’re not there:

  • Keep toys out. "They're colorful. They're made to attract kids," Drengenberg says. "It will attract them to the pool."
  • Consider investing in a power safety cover, a motor-powered barrier that covers the water, the CPSC suggests. This is a cover you would use daily when the pool is open — it’s different from the cover you use in the winter.
  • For above-ground pools, remove any steps and ladders after you’re done with the pool, the CPSC recommends.
  • Consider installing a pool alarm. The CPSC recommends looking for one that meets the standards of ASTM International, an international standards organization, and comes with a remote alarm receiver so you can hear the alarm when you’re away from the pool. There are different styles of pool alarms, but many sit in the water, and when waves are created (perhaps by someone falling in), the alarm goes off.

Lastly, keep emergency rescue equipment, like a foam ring buoy or rescue pole and hook, by the pool, the CPSC advises.

When kids are in the pool

When the pool is being used, even more vigilance is needed. Drengenberg says parents should employ the "10-20 rule." That is an adult, whose undivided attention is on the pool, should scan the pool every 10 seconds and be within 20 seconds of getting into the water if there's a problem.

Child swimming underwater (Photo: Sergey Novikov/Shutterstock)

"It means you're watching the pool. You have to do that," says Drengenberg. "If you have children in a pool you need adult supervision. The adult supervision has to be an adult paying attention to a pool."

Even if you have a 12-year-old who is a great swimmer, he or she is not a substitute for an adult, Drengenberg says. Children are easily distracted and should not be responsible for the safety of younger children.

The adult should have a phone handy in case there’s a need to call for help in an emergency. He or she should also know CPR.

Related: How — and — When to Perform CPR

The most difficult situations involve larger gatherings, says Drengenberg. It’s often at these gatherings that accidents occur. When many children are in the pool it can be difficult to keep track of all of them. And the longer someone is underwater, the less chance there is to save them.

For that reason, Drengenberg says, if a child is missing and there's a pool, the first place to look is always the pool. Don't waste time first looking around the house, calling the neighbors or running around the yard.

Drengenberg also urges parents to not be lulled into thinking small, inflatable wading pools are any less dangerous than larger pools. Just because the water is relatively shallow doesn't mean a toddler can't drown in one. Kids can drown in just a few inches of water. You still have to watch them around wading pools and make sure the pools are safe when not in use.

"When you're done with it, as inconvenient as it might sound, dump it out," he advises. "And make sure you turn it upside down so the rainwater doesn't accumulate."

Related: 7 Things to Do Now to Make Your Home Safer For the Summer

Mitch Lipka is a consumer columnist and product safety expert. He was the 2011 recipient of the "Kids Best Friend Award" from Kids In Danger for his commitment to reporting on children’s product safety.