A more extensive extreme heat policy is set to be introduced at the Australian Open 2019 as a result of cutting-edge research and testing into the specific effects of heat stress on tennis players.

The research, conducted by Tennis Australia medical personnel in conjunction with the Thermal Ergonomics Laboratory at the University of Sydney, has led to the development of the Australian Open Heat Stress Scale (AO HSS).

There will also be more comprehensive measuring of weather conditions at Melbourne Park, and an increase in measuring devices across the site,

Australian Open Tournament Director Craig Tiley said his team was constantly looking for ways to improve the conditions for the players.

“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,” 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."

"The AO Heat Stress Scale takes advantage of the latest medical research into the effects of heat on the human body including the maximum heat stress an athlete can safely withstand, the sweat rate of that person and their core temperature," Tennis Australia Chief Medical Officer Dr Carolyn Broderick said.

“The scale also accounts for the physiological variances between adults, wheelchair and junior athletes while also taking into account the four climate factors – air temperature, radiant heat or the strength of the sun, humidity and wind speed – which affect a player’s ability to disperse heat from their body."

With new technology and information available, these four climate factors will be accurately measured in real time at five different locations across the Melbourne Park precinct. This provides more information than the previous Wet Bulb Globe Temperature (WGBT) readings from the Bureau of Meteorology.

About the 2019 Extreme Heat Policy:

Under the new extreme heat policy, the Tournament Referee will allow a 10-minute break between the second and third sets in both women’s and junior singles matches and a 15-minute break in wheelchair singles matches when a four (4.0) is recorded on the AO HSS prior to or during the first two sets of the match.

If a five (5.0) is recorded on the AO HSS, the Tournament Referee can suspend the start of matches on outside courts and all matches in progress continuing until the end of an even number games in that set or completion of the tiebreak 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 tiebreak when the Tournament Referee can decide to close the roof for the remainder of the match and the following matches, when the extreme heat policy is still in effect.