Due to extreme heat, the 2007 Chicago Marathon proved to be a grueling event. Over 30% of the participants didn't finish the race, 250 were treated for heat related injuries, and 50 runners were taken to the hospital.

In a MyFox Chicago report, MOR surgeon Dr. Jeffrey Mjaanes discusses precautions that this year's marathoners can take to stay properly hydrated and protect themselves against changing weather conditions.

To view the video segment, click on the link below.

MyFox Chicago Report: On the Run