Alize Cornet warns 40C Australian Open conditions are 'very dangerous' after suffering dizziness

Alize Cornet claimed that playing in 40C temperatures was “very dangerous for the health of the player” as Australian Open organisers decided not to invoke their extreme heat policy on Friday.

Cornet, who suffered with dizziness and sent for the doctor during her 7-5, 6-4 defeat by Elise Mertens, was one of several players who suffered in the heat. The 27-year-old Frenchwoman complained that the tournament’s criteria for halting matches needed to be lowered.

A combination of heat and humidity readings are used to determine whether conditions are too extreme for play to continue. If those thresholds are reached, the roofs on the three main show courts are shut and matches on the outside courts suspended. Despite Friday's intense heat, the humidity readings were comparatively low.

Petra Martic, who beat Luksika Kumkhum 6-3, 3-6, 7-5, took painkillers to deal with blisters on her feet which she said had been caused by the heat coming off the court surface, while Marta Kostyuk, who at 15 was the youngest singles player to reach the third round of a Grand Slam tournament for 21 years, said her energy levels had dipped in the heat as she was beaten 6-2, 6-2 in just 59 minutes by fellow Ukrainian Elina Svitolina.

Coco Vandeweghe has been fined more than £7,000 for unsportsmanlike conduct after shouting an obscenity at first-round opponent Timea Babos.