“Turn off that screen and go outside and play!” It’s a refrain that echoes across the land as we move toward the long, school-less days of summer.

Outdoor exercise and unstructured play time are important for kids, and American children often get too little of both. But if playing outside means using the backyard play structure or swing set, make sure it’s safe before you boot the kids out the door.

About 50,000 kids visit U.S. hospital emergency rooms each year as a result of injuries from home playground equipment. Here’s a pre-flight checklist to help ensure your play structure is safe.

Related: Is Your Child’s Playground Safe?

Tighten the bolts. Your structure may be made of wood, metal, plastic or any combination of the three, and different materials expand and contract at different rates during seasonal temperature changes. That means bolts can come loose over the winter even if nobody is using the play structure. Swinging and climbing also can loosen bolts. So tighten all the connections before the kids hit the backyard and every couple of weeks during the play season.

Check for bolt caps. While you’re inspecting the bolts, make sure each has a plastic cap that covers little section of bolt that protrudes through the nut. Over time, these caps can deteriorate and slip off. Exposed bolts can lacerate kids and entangle clothing — a strangulation hazard. You can buy these bolt/screw protectors at the hardware store.

green plastic screw protector

(Photo: The Hillman Group)

Inspect the S-hooks. Make sure all S-hooks are closed tightly enough so that you can’t fit a dime through the space at either end. An open S-hook could catch clothing (another strangulation hazard), and a hook on a swing could disconnect if a child swings high enough. If an S hook is open, squeeze it shut with a large pair of pliers.

Check the anchors. Some play structures need to be anchored to prevent tipping. Check the manufacturer’s instructions for information on proper anchoring. Make sure the anchors are buried so kids won’t trip on them.

Say nope to rope. Creative kids like to augment their play structure with extra ropes to swing or climb on. Don’t let them attach jump ropes, pet leashes, clotheslines or cords of any kind to the play structure. They’re a strangulation hazard.

Look for deterioration. Sand down any splinters that may have developed on wooden parts over the winter. Check each month to ensure that swing seats, chains and cables are intact and ropes are not frayed. Replace if necessary. Clean, sand and repaint rusted areas with a rust-resistant paint designed for outdoor use on metal.

Clear the area. Make sure that there are no obstructions such as the house, shed, fence or overhead wires within 6 feet of the play structure. Trim back any low overhanging tree limbs.

Renew the mulch. You’d never put a play structure over hard surfaces such as concrete or asphalt, but did you know that grass also is not a safe surface? The pounding of little feet will kill the grass and compact the soil into a hard surface. Mulch is the most common safe choice for home playgrounds. Put down a 12-inch-deep layer to start — it will compact down to the 9 inches recommended for under a swing. Then periodically add mulch to maintain the 9-inch depth.

If replenishing mulch seems like too much of a chore you can use rubber tiles or a poured-in-place surface. These surfaces require professional installation. Ask the installer for a report showing that the surface meets the ASTM F1292 safety standard.

Does your play structure meet current safety standards?

Perhaps the play structure was there when you bought the house. Or maybe you’re planning to buy a new one, or you’re an ambitious do-it-yourselfer who wants to design and build your own. In any case, you’ll want to make sure the structure meets current standards. For example all the openings — such as between ladder rungs, posts and railings should either be smaller than 3 ½ inches so kids can’t get their heads through, or larger than 9 inches so they can slide their body and head through.

You’ll find all the pertinent standards and other safety info in the Outdoor Home Playground Safety Handbook from the U.S. Consumer Product Safety Commission.

Keep your eyes open

Young kids are clever. They constantly test their own abilities, often without recognizing potential hazards. Experts estimate that more than 40 percent of playground injuries are directly related to a lack of supervision. Your play structure may meet every safety standard in the book, but that’s no substitute for the constant supervision of an attentive adult who is right on the spot. So get out there with them. You could use the fresh air too!

Related: Life-Saving Water Safety Tips: Making Your Pool a Drowning-Free Zone

David Schiff is a freelance editor and writer who specializes in home safety, home improvement, woodworking, child safety and music.