A boy in Maryland was seriously burned when he stepped onto a black rubber mat at a playground with bare feet.
The mats are made of recycled tires and provide padding in case of a fall, but they can also absorb heat.
Some recent tests on playground equipment found a slide that reached 126 degrees. Tests on the blacktop showed temperatures of 132 degrees, and rubber padding reached 142 degrees.
Paramedics say human skin begins to burn at 124 degrees.
