Melbourne - Extreme heat forced organisers to suspend play for several hours at the Australian Open on Thursday following days of complaints about "inhumane" conditions which left some players fainting and vomiting.
With temperatures hitting 42 degrees Celsius (107.6 Fahrenheit), officials finally called a halt just before 14:00 local time, hauling players off courts and closing the roofs on the two main arenas.
The rare shutdown was the first in five years and follows near-record heat in Melbourne which buckled tramlines and prompted 1 000 bushfires in the surrounding state.
The full schedule did not resume for four hours at 18:00, at the start of a busy evening as players worked their way through a packed agenda of second-round singles matches plus doubles.
Some competitors have been furious about playing in the oven-like heat after several fell ill during their matches. Britain's Andy Murray warned organisers were risking a tragedy.
Canada's Frank Dancevic said he hallucinated a vision of cartoon dog Snoopy before blacking out, and China's Peng Shuai vomited and cramped up during her loss to Kurumi Nara.
Ivan Dodig said he was afraid he was about to die after suffering severe cramps and retiring after four sets of his match against Damir Dzumhur.
America's Varvara Lepchenko was the latest victim on Thursday when she had her pulse and blood-pressure checked and was rubbed down with ice by staff during a medical time-out.
"Some of the girls can't even talk after the match or practice," said Polish fifth seed Agnieszka Radwanska.
Maria Sharapova was unlucky when the halt was announced during her third set against Karin Knapp, meaning she could not come off until it was over. The third set went to 10-8, lasting nearly two hours.
Afterwards, the Russian star questioned the policy of making players finish their sets and said organisers should be more open about when and why play will be suspended.
"There is no way getting around the fact that the conditions were extremely difficult, and have been for the last few days," she said.
"I mean, I think the question I have is no one really knows what the limit is. Not the players; the trainers themselves, when you ask them when will the roof be closed?"
Attendances have dropped sharply since Monday's first-day record of 47 491. On Wednesday, the figure was about a third lower, at 32 911.
Melbourne Park's outdoor stadiums took on the surreal air of waiting rooms on Thursday as spectators fanned themselves and sucked ice lollies while waiting for the action to restart.
Only a small crowd braved the venue's unshaded garden area to watch the big-screen broadcast of home hope Thanasi Kokkinakis taking on world number one Rafael Nadal in the closed Rod Laver Arena.
"Doing physical exercise in this heat is just unbelievable," said France's Alize Cornet. "Even for the fans, sitting in the sun must be terrible."
Thursday's temperatures peaked at 43.4 Celsius in mid-afternoon and the heat was forecast to reach 44 Celsius on Friday before dropping sharply on Saturday.
The readings make it one of Melbourne's worst heatwaves, comparable to 2009 when severe bushfires in the surrounding state devoured entire towns, killing 173 people.
The 2009 Australian Open, when the extreme heat policy was last enforced, was also the hottest on record with an average daily temperature of 34.7 Celsius.
Organisers did not give an immediate response when asked to comment on the players' criticisms about the heat policy. At 19:00, the temperature remained at 40 Celsius.