Just to illustrate the point about the dangers of concussion - This is a quote from an article on Concussion from emedicine: "The second injury syndrome (SIS), although rare, is important as a cause of preventable sudden death. SIS occurs when someone not yet fully recovered from a head injury experiences another head or upper body injury, even seemingly trivial injury." It is a huge deal when somebody has a second injury after an initial concussion. There has been a big push to bring this to the fore in the hockey leagues in North America following deaths of kids who initially had "minor" concussions and played soon after and received a second injury to the head. As a physician for 23 years I know a little of what I am talking about. Those of you with no medical knowledge should be careful about showing your ignorance.