JACKSONVILLE, Fla. -- More babies are developing flat head syndrome, a condition that can be permanent if parents don't act fast.

Flat head syndrome is the side effect of the "Back to Sleep" campaign to reduce SIDS deaths in babies. Parents are told to always put their infants to sleep on their backs. Now many of those babies' skulls are flattening.

Evan, who's just 10 months old, makes many trips to physical therapy for the condition. The back of his head looks OK now, but it was much flatter just four months ago.

"Rather than having a cup to it, a cup to the back of his head, it was his neck and then straight up," said Paul Mucciolo, Evan's father. "It was completely flat. It was as if you could put a board to the back of his head."

Evan's dad is an emergency room doctor, and he knew something wasn't right. So he took Evan to Wolfson Children's Hospital to see Dr. Louise Spierre.

"So by about four months of age, about 20 percent of children will have some degree of significant flattening with the back of the head," Spierre said.

He said sometimes the head corrects itself, but not always. That's when a special helmet may be needed.

Evan's been wearing one for three months. He recently had a scan done to measure how well his helmet has reshaped his skull.

"We have a nice rounded head and circum spine that I think he's got pretty much where he's going to be," Spierre said.

Spierre said the helmet has been working for Evan.

"The point is to put pressure on parts of the skull that are sticking out," he said. "As the head continues to grow, it will become rounder."

"It's 23 hours a day," Mucciolo said. "He'll wear it all day and all night. The only time he'll take it off is for bath time, so we'll take it off then."

The catch is that Spierre said flat head syndrome has to be caught by about 6 months of age.

"Eighty percent of head growth is in first year of life," Spierre said. "The helmets only work in the first year of life."

Evan has to wear his helmet a bit longer, which means his parents have to deal with his crying and stares for now.

"Some people's eyebrows go up because it's, 'Oh, what's that," Mucciolo said. "A baby has a big head compared to his body anyway. When you put this on it looks enormous."

All Evan's parents care about is their baby's health, and they don't regret for a minute getting him the help he needed.

"What's three months of correctiveness for a lifetime of (health)," said Kristi Mucciolo, Evan's mom. "I didn't want him to come back to me and say, 'Mom, why didn't you do something when you could have done something.'"

There are some things you can do to prevent flat head syndrome.

Spierre said starting at 2 months old, you need to put your child on their tummy for at least 15 minutes twice a day.

Make sure your child is awake and supervised. You should never leave your infant alone on his or her stomach.

Spierre said swings don't have a lot of padding for the back of the head, so she suggests not letting your infant sit in them more than 10 minutes at a time, and don't let your baby sleep in them.

If you start seeing your child's head flatten and it doesn't correct itself by the time the child is 6 months old, talk to your doctor right away.

For no reason should you stop putting your children to sleep on their back. Back sleeping has reduced the number of SIDS deaths by 50-percent.