Kei Nishikori of Japan holds ice packs to his face during his match against Dusan Lajovic of Serbia at the Australian Open. Picture: Jason Reed

Melbourne – Play on the outer courts at Melbourne Park was called to a halt on day four of the Australian Open on Thursday with temperatures hitting 41 degrees Celsius and still rising.

Organisers, who had been slammed for forcing players to play on in searing temperatures on Tuesday and Wednesday, enacted the third stage of their “Extreme Heat Policy” for the first time at about 1.50pm local time (4.50am SA time).

Play would continue in all matches until the end of the ongoing set and then cease until conditions eased, organisers said in a statement.

The exception would be on the Rod Laver Arena and Hisense Arena show courts, where play would resume after the retractable roofs were closed.

“For outside courts new matches will not be called to court until the temperature falls back down to a temperature deemed fit for play by the tournament director,” read a statement from organisers.

With forecast highs of 44 degrees Celsius, a third straight day of suffocating heat at the year's first grand slam was guaranteed to keep the debate on whether play should continue rumbling on.

On Tuesday, when temperatures peaked at 42.2 degrees, Canadian Frank Dancevic passed out during his first round match and accused organisers of forcing players to play in “inhumane” conditions.

Ivan Dodig became the 10th player to retire in the first three days of the tournament on Wednesday and said he feared for his life after being rendered immobile by the heat on the exposed outer courts.

Under a change to the rules for this year, the decision on whether to stop matches at the tournament is now at the discretion of tournament director Wayne McKewen.

Rather than use the raw Celsius readings to assess the heat, organisers prefer to use the Wet Bulb Global Temperature composite, which also gauges humidity and wind to identify the perceived conditions.

McKewen said that the threshold was not reached on Tuesday and Wednesday with world number seven Tomas Berdych suggesting that perhaps it had been set too high.

The hot weather is forecast to continue through Friday before a dramatic drop in temperatures at the weekend. – Reuters