Reasons for Victoria Azarenka’s collapse at US open

Question

As temperatures soared at the US Open on Wednesday, 10th seed Victoria Azarenka was forced to retire from her second round match against Gisela Dulko after collapsing at the back of the court. Find out the reasons for her collapse at http://blogs.bettor.com/Victoria-Azarenkas-US-open-collapse-the-reasons-a24970.