There is no better idea than building a backyard tent  that will protect children from overheating on sunny days.  For it you’ll need an extra large sheet, a yard of rope, 4 long stakes, a hammer to secure them in place. Tie your rope to two parallel stable objects, tying it about a foot higher than you want the tent’s ceiling to be. Take your sheet and tie loose knots into each corner and center it over your rope. Pull the corners out and down to the ground as markers so you know where to hammer your stakes into the ground. Once they’ve been hammered far enough that there isn’t any wiggle room, pull your loose knots over the stakes and tie them tight. Fill your fort with pillows and blankets, and you can drive the children inside.