The "AOHeat Stress Scale" will be used for the first time at a Grand Slam to help prevent heat stress on players.

The new policy, which takes over from the previous Wet Bulb Globe Temperature reading, is set to be able to provide more accurate information from the Melbourne Park precinct about the four climate factors.

The change comes after players expressed their dismay at the previous heat policy used at the 2018 edition of the Australian Open. 

A court temperature reading of 69C was recorded during a men's singles match while German Andrea Petkovic said she could not think straight during her match.

“The wellbeing of all players at the Australian Open is our utmost priority and we have developed the Australian Open Heat Stress Scale after months of research and testing,” AO Tournament Director Craig Tiley said.

“The AO Heat Stress Scale ranges from one to five with specific recommendations associated with each step of the scale – one denoting temperate playing conditions and five the suspension of play."

Under the new policy, there will be a 10-minute break between the second and third sets in a women’s singles match when a four (4.0) is recorded on the scale prior to or during the first two sets of the match.

If a five (5.0) is recorded play can suspend the start of matches on outside courts and all matches in progress would continue until the end of an even number games in that set or completion of the tie break before play will be suspended.

Matches on Rod Laver Arena, Margaret Court Arena and Melbourne Arena will stop after an even number of games in that set or completion of the tie break and the roof can be closed for the remainder of the match and the following matches.