CHICAGO (CBS) — The hits just keep on coming for school age football players and other sports. Those hits can be catastrophic.

Now the city of Chicago is taking action to protect young public school athletes and prevent concussions from doing serious damage, CBS 2’s Mike Parker reports.

A high school linebacker can possibly take 6,000 hits to the head during three seasons, and those hits can cause damage.

Now a new Chicago law is on the books.  Athletes at city schools who show signs of possible concussion cannot return to their sport without a doctor’s permission.

That is good news to one time professional wrestler Chris Nowinski.  He suffered six concussions, and they took their toll.

“I had headaches for five years.  I had sleepwalking for three years, short-term memory problems for a year and a half. It really took away my twenties,” Nowinski says.

Thursday night, he and some other former athletes gathered in Chicago to raise money for programs to educate youth, coaches and players about the dangers of head injuries.

Former Bears quarterback and Super Bowl champion Jim McMahon was there.

“When you’re young, you think nothing can bother you,” McMahon says. “You can injure your brain for the rest of your life.”

He knows better now.  McMahon says he noticed that after he retired, his memory started to go.

“I don’t think it’s chronic yet, but it’s frustrating when you walk into a room and you forget why the hell you went in there. You’ve got to start all over again,” he says.

It can get much worse. Boston University has studied the brains of 13 deceased pro football players. Twelve of the 13 had a disease that causes dementia. McMahon is now disclosing that when he dies, his brain will be donated to aid in this research.