Generally, twice as many adults are needed to adequately supervise children. Check that rain water has not collected in outdoor containers. Do not leave water in cleaning pails. Kids can drown in just two or three inches of water. Be particularly alert for injuries caused by fighting or pushing when the heat rises.
Hot days are particularly hard times for children to have to wait.
Offer lots of cool clean water for them to drink throughout the day. Provide rest times for kids to slow down and be out of the sun. Make sure there are shady spots available to kids. If there is no shade, a sheet hung over a climbing structure or outdoor furniture offers protection from the sun as well as a special place to play. Metals slides facing south can get hot enough to burn.