And its results. In the video below you will see tennis professional Victoria Azarenka collapse on the court at the US Open in New York.
http://www.youtube.com/v/pBOy8KZzgVA?fs=1&hl=en_US
Although the conditions were hot, and she had been complaining of abdominal pain earlier in the week, it was later found out that Azarenka sustained a concussion just prior to the match. While warming up for the match she fell and hit her head. The doctors and official report blame the fainting on the concussion.
I had missed this story until today, with the thought it was heat related, but after further investigation, it was yet another example of a poorly handled concussion.