Australian Open: Can't stand the heat? Try Bikram yoga

    By Tom McGowan, CNN

    Updated 1859 GMT (0259 HKT) January 15, 2014

    Li Na faced a battle to stay cool and to stay in the Australian Open against Lucie Safarova.
    Photos: Australian Open hots up
    Australian Open hots up – Li Na faced a battle to stay cool and to stay in the Australian Open against Lucie Safarova.
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    Li's compatriot Zheng Jie needed medical treatment for heat stress during her 6-2 6-4 defeat by Casey Dellacqua. "I felt so hot, my mind wasn't working," said Zheng. "I was looking at the ball, but I couldn't focus on it. Then I couldn't concentrate. This weather is very difficult for me.<br />
    Photos: Australian Open hots up
    Medical treatment – Li's compatriot Zheng Jie needed medical treatment for heat stress during her 6-2 6-4 defeat by Casey Dellacqua. "I felt so hot, my mind wasn't working," said Zheng. "I was looking at the ball, but I couldn't focus on it. Then I couldn't concentrate. This weather is very difficult for me.
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    Serena Williams looked in complete control during her straight-sets win over Vesna Dolonc on Wednesday, but the top seed admitted to waking up in the middle of the night due to fears over dehydration.