Players criticise sweltering conditions at Australian Open as temp hovers at 40 degrees

Some weary players sat shirtless on changeovers, ice-filled towels draped around their necks. Others retreated to any bit of shade they could find on court and sought treatment for blistered feet and heat stress.

Temperatures soared to 40 degrees as the start of an expected heat wave hit the Australian Open on Thursday, bringing misery to players unfortunate enough to have their matches scheduled during the day session and keeping many spectators away.

"I didn't expect to play this kind of match," a thoroughly exhausted Juan Martin del Potro said after beating Karen Khachanov in a nearly four-hour, second-round match.

The ASB Classic tournament second seed took time out to sign autographs and pose for photos. Source: 1 NEWS

"I prefer to watch on TV. Or stay on the beach, drinking some beer."

Scorching temperatures are common at the Australian Open — so much so the tournament has an extreme heat policy that allows for the referee to close the roofs on the three main show courts and suspend play on the outer courts when temperatures surpass 40 Celsius.

Gael Monfils staggered through a good portion of his second-round match against Novak Djokovic, bending over repeatedly to catch his breath between points and at one stage returning to the comfort of his shaded chair without even attempting to return Djokovic's serve.

Afterwards, he called the conditions "risky" for the players, especially with the new rule restricting the time between points to 25 seconds.

"I get super dizzy. I think I have a small heat stroke for 40 minutes," said Monfils, who is considered one of the fittest players on tour.

"At that time, the officials have to make a move. Maybe wait a little bit, whatever, five minutes between the set. Maybe they have to do small adjustment."

Djokovic agreed, describing the conditions "brutal" and some of the toughest he's ever played in.

"There are certain days where you just have to, as a tournament supervisor, recognise that you might need to give players few extra hours until (the temperature) comes down," he said.

"I understand there is a factor of tickets. If you don't play matches, people will be unhappy."

But he said the conditions were at the point where it becomes a "danger in terms of health."