It's so hot that the extreme heat policy was put into effect, which allowed a 10-minute break after the second set for women and after the third set for men.

While 2011 US Open Champion Sam Stosur told AAP after her first round loss that is wasn't enough time with players needing to cool off, change, hydrate, and prepare once again to step onto the court.

“What’s 10 minutes in the span of a whole day if it means the safety and health of the players for sure?” said Stosur.

For French player, Alize Cornet, she decided to change clothes but soon realised her shirt was on the wrong way. So she took the chance after dropping the second set to Swede Johanna Larsson to take off the shirt and put it back on the right way.

However, chair umpire Christian Rask hit her with a code violation.

According to the 2018 WTA rulebook, "a player can only change clothes during the end of a set, or during a medical timeout, in an off-court location". Due to it being a warning, she did not have any points taken from her.

It sparked a storm on social media with Former Great Britain Fed Cup captain Judy Murray, who is also the mum of Andy Murray, took to Twitter to express her disappointment.

Cornet, who went on to lose 6-4, 3-6, 2-6, describe the conditions as a "nightmare" and that she was telling doctors that she was ready to vomit as she sat courtside.