BOSTON -- With temperatures heating up outside- safety experts have a warning for parents. As NewsCenter 5's Heather Unruh reported, a hot summer day can turn a fun playground into a dangerous place.

Annabelle LaPlante will likely need plastic surgery after getting severely burned at a playground in Loveland, Colo.

"It happened in a split second," said Jeni LaPlante, the girl's mother.

Annabelle was kneeling on a platform playing tic tac toe, when she suffered a third degree burn from her knee to her ankle.

"Just for a trip to the playground," LaPlante said.

Safety experts warn this is not an isolated incident.

"We don't see it very frequently, but certainly there is some risk that children can sustain superficial burns," said Dr. Lois Lee, of Children's Hospital Boston.

On a hot day with 100 degree heat, temps can reach more than 150 degrees on playground equipment. A 120-degree surface takes less than three seconds to burn a child's skin severely enough to require surgery.

Safety expert Wendy Forbes demonstrated how hot a Colorado playground can get.

"Let's give this one and see what we got. It's stopping at 117 degrees," Forbes said. "It's jumping up into the 150s. That's why it's very important for parents to dress their children appropriately."

You don't need a heat gun to demonstrate how hot it can get.

"My recommendation for parents is always to touch the playground equipment themselves before they let their child get onto it," said Lee.

We used our hand to test the surfaces at a playground in West Newton, Mass. just before noon on Tuesday. The slides were so hot, we had to pull our hand off in less than two seconds.

As for Annabelle, doctor's say she may need skin grafts.

"This is preventable. Very preventable," said LaPlante.