A concussion is a brain injury characterized by impaired cognitive or physical functioning that is caused by a blow to the head, face or neck or a blow to the body that causes a sudden jarring of the head. Students who sustain such a blow will be removed from activity immediately. If it is suspected they have a concussion, they may not return to any extracurricular physical activity until their health-care provider provides a written medical release. Parents are encouraged to notify the school nurse if their child sustains a concussion during a non-school activity. For more information, see School Board Policy 4135 located online at mychesterfieldschools.com under the School Board tab in the School Board policies section.