The Australian Open is already underway after a very entertaining first day in Melbourne. However, while the action on the court has gone smoothly, the tournament has faced a number of difficulties of late.

The first Grand Slam of the season has had to contend with the bushfires that almost caused the entire Open to be postponed three years ago, the severe restrictions imposed by Covid-19 in the midst of a pandemic and, of course, the heatwave of the mid-Australian summer.

But what exactly do tournament organizers do when temperatures reach dangerous levels and what procedures are in place to protect players?

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What is the Australian Open ‘extreme heat rule’?

The Australian Open introduced an ‘extreme heat rule’ in 2019 as a result of research into the effects of heat stress to tennis players.

The research led to its implementation Heat stress scale which can help tournament organizers complete whether or not it is safe to continue with a race in extreme heat.

“The AO thermal stress scale ranges from one to five, with specific recommendations associated with each rung of the scale: one indicates mild playing conditions and five means suspension of play”said Tournament Director Craig Tiley.

1. Moderate the playing conditions
2. Increase hydration
3. Implement cooling strategies
4. long breaks
5. game suspension

The four main factors that dictate scale results are: air temperature, radiant heat, humidity and wind speed.

“The AO Heat Stress Scale takes advantage of the latest medical research on the effects of heat on the human body, including the maximum heat stress that an athlete can safely withstandthat person’s sweat rate and core temperature”explained Dr Carolyn Broderick, Tennis Australia’s Chief Medical Officer.

A heat policy has been in place at the Australian Open since the late 1990s, but has been constantly modified as more research and evidence has become available.

When are matches at the Australian Open canceled due to heat?

The tournament referee will allow it a long break between the second and third sets in women’s competitions when the score on the heat stress scale is four.

For men, this 10-minute break will apply after the third set if a “four” is recorded on the EET before or during the first two sets of the match.

However, If five is recorded on the EET, the referee may decide to postpone the start of games in outdoor stadiums.

Matches played during this period may also be suspended once an even number of matches is reached in the particular set in which it is played.

What is the Australian Open Heat Stress Scale?

Before its introduction Heat stress scale Four years ago, the Australian Open had a policy that was not so clearly defined.

Now, EET provides clear instructions must be followed in case of hot track temperatures.

The scale prioritizes heat prevention in the lower phases, with increased hydration measures and cooling strategies used to help athletes. However, once it reaches five points, the game is paused.

The current edition has been around since Novak Djokovic and Gael Monfils met at the 2018 Australian Open in difficult conditions that led to both players raising concerns about the tournament’s politics.

“I think there are certain days where you just have to, as a tournament supervisor, recognize that you might have to give players a few extra hours until it drops.”Djokovic said then.

“I think there’s a line, and it’s a level, I guess, of tolerance between being fit and being, I think, at risk from a health standpoint.”