A Stratford High School football coach is apologizing Tuesday after more than a dozen of his players left practice with burns and serious blisters on their hands.

Coach T.J. Cavaliere says he asked the entire team to crawl across the football field after several players misbehaved. He says he did not realize that the artificial turf on the field heats up as the outside temperature increases.

Cavaliere tweeted out an apology and sent a letter home to parents. "I apologize for what happened and have learned a valuable lesson," he wrote in the letter. "I was not aware that the turf would cause blisters on the boys' hands ... had I known that this would have been the outcome I would have selected a different exercise."

Some parents are saying that sorry isn't enough.

A parent told News 12 that it looks as if her son suffered second-degree burns because the skin on his hand has completely peeled off.

News 12 contacted Stratford school leaders, including the coach and athletic director, for comments. They did not return the calls.

The superintendent says she is still investigating the incident.

Parents had plans to meet with school leaders Tuesday, but the meeting was canceled because students were dismissed early due to the hot weather.