context: Playing outside in the backyard is a natural pasttime for most kids. Keeping that outside environment safe is key to keeping children healthy and injury-free. Each year, more than 200,000 children go to emergency rooms for playground-related injuries. And while deaths from such injuries are rare, most happen at home. Supervising your child at play is a big factor in reducing injury. And taking these playground precautions will also reduce risk: Cover areas under and around the playground equipment with shock-absorbing material, such as sand, rubber, or mulch, 9-12 inches deep. Make sure swing seats are made of soft rubber, not hard wood. Don't suspend more than two swing seats in the same section of the equipment's support structure. Most home playground injuries can be blamed on swings. The equipment should have ladders with steps rather than rungs for easier access, or rungs with more than nine inches or less than three and a half inches of space between them, to prevent children from getting stuck. Cover all protruding bolts. Do not attach ropes or cords to the play set, which could become strangulation hazards. Plastic play sets or climbing equipment should never be used indoors on wood or cement floors, even if they're carpeted. All climbing equipment should be outdoors on shock-absorbing surfaces to prevent children's head injuries. Slides and platforms should be no higher than six feet for school-age children, or four feet for pre-schoolers. Platforms, walkways, ramps, and ladders should have adequate guardrails. Protect against tripping hazards such as tree stumps, concrete footings, and rocks. During hot summer days, check the temperature of the slides and swings, because they can become hot enough to cause burns to the skin. Arsenic in pressure-treated wood -- used in play sets, decks, and picnic tables across the country -- poses an increased risk of cancer to kids who play and eat on wood surfaces, according to the EPA. Many outdoor wooden structures in the U. S. are made from arsenic-based treated wood. While the wood industry phased out production of this type of wood in 2003, existing structures are still a concern. To protect your children from arsenic exposure, take the following measures: Seal the wood at least once per year with standard penetrating deck treatments. Replace potentially high-exposure sections such as handrails, steps, or deck boards with non-arsenic alternatives. Keep children and pets away from the soil beneath and immediately surrounding arsenic-treated wood structures. Cover arsenic-treated picnic tables with a tablecloth before using. Do not pressure-wash to clean the surface of arsenic-treated wood. Instead, use a soap and water solution, with disposable cleaning supplies. Do not allow children to play on rough wood surfaces. Arsenic-treated wood splinters can be dangerous. Do not store toys or tools under the deck. Arsenic leaches from the wood when it rains and may coat things left there. Do not use commercial "deck washing" solutions. These solutions can convert chemicals on the wood to a more toxic form. Drowning is a leading cause of death to children under age 5. And many drownings occur at home. Take these simple precautions: Always supervise children who are in and around a pool or spa. Infants and toddlers should never be in the pool without an adult in the pool with them and at arm's reach away. NEVER allow anyone to swim alone. Consider setting rules for play such as no running, no diving, and no pushing. Have fences or walls at least four feet high completely around the pool. Gates should be self-closing and self-latching, open outwards, with latches out of reach of children. Fences should be clear of objects that a child could use to climb over fence, such as BBQ grills and lawn chairs. Keep rescue equipment by the pool, including a portable or mobile telephone. Steps and ladders for aboveground pools should be secured or removed when the pool is not in use. Toys should also be kept away from the pool when they are not in use. Use a cover for the pool when it is not in use. Make sure drain covers are properly fitted and paired or have vacuum suction releases to prevent being trapped under water. Consider installing a pool alarm that can alert if someone enters the pool. Spa water temperatures should be set to 104 F or lower to avoid elevated body temperature, which could lead to drowsiness, unconsciousness, heat stroke, or death.