World number four Agnieszka Radwanska said it was "too hot to
play tennis" and China's Li Na said it was like a sauna as the Sydney International was hit by a searing heatwave on Tuesday.
Poland's Radwanska battled fearsome temperatures topping 40 degrees celsius to brush past Japanese veteran Kimiko Date-Krumm 6-4, 6-3.
Li Na, who beat Japanese qualifier Ayumi Morita 6-1, 6-0, said that she was reaching for the ice towels at each changeover.