According to the National Recreation and Park Association, an estimated 40 percent of playground injuries occur because children are not being properly supervised. It is the responsibility of teachers and adults to watch the children, but the children should also be told to stay where they can always see an adult. If there are certain areas of the playground that are difficult or could cause injury to a child, like a climbing wall or a platform that children like to jump off, they should know that doing those activities is allowed only when an adult is standing there to help them if necessary.
All children but especially boys may try to work off some of their excess energy by wrestling or jumping on one another like they might see done on television or by older brothers at home. Make a rule that roughhousing and wrestling are not allowed on the playground and explain that they can hurt other people by doing it.
Some playgrounds have sand pits or are built on wood chips, and children will certainly be down on the ground picking up handfuls of these materials. When they're playing a game or if they get angry with a friend, a child may throw the sand, dirt or wood at another child. These materials can cut a child's skin or get into his eyes, so there should be a rule that the sand and wood stay on the ground at all times.
Whenever a child is new to the preschool and the playground, adults should demonstrate the right way to use all the playground equipment. For instance, show the child how to go down the slide sitting on his bottom with his legs in front of him and his arms close to his body, then mimic some unsafe behaviors that are not allowed on the slide, like riding down on his belly. Do the same thing with all the equipment on the playground so all the children know exactly what is safe to do and what is not.
If teachers are providing proper supervision, strangers should not be allowed to get near the playground while children are playing, but there is always a chance that a dangerous person could get close to the children. Make sure all children know not to talk to any strangers on the playground and that if they see any people nearby whom they don't recognize, they should tell a teacher immediately.