ABC News' Clayton Sandell reports:

Formula One champion Michael Schumacher is used to danger at 200 miles per hour.

But skiing the French Alps Sunday, he fell, slamming his head on a rock. Schumacher was severely injured but reportedly still conscious and talking when he reached a hospital 90 minutes later.

"It's extremely common for a person to be initially awake after a head trauma, even a substantial head trauma," Dr. Peter Warinner of Brigham and Women's Hospital said.

Schumacher's condition rapidly spiraled downward. He was rushed into emergency surgery and put into a coma.

Doctors say Schumacher would have surely died on the slope if he hadn't been wearing a helmet. A record number of United States skiers are now wearing them. One estimate from the National Ski Areas Association says up to 70 percent.

"You are safer but it's not going to protect you from everything," Brendan Irving of the Winter Park Ski Resort said.

Doctors say if you hit your head hard while skiing, even if you're wearing a helmet and feel fine, get checked out. Your brain could be starting to swell or bleed.

As Schumacher hangs on to life, doctors say his helmet has given him a fighting chance.

(Clive Mason/Getty Images)