Source : ABC NEWS
The Australian Open makes headlines every year for the on-court antics, but sometimes the focus shifts to a force beyond players’ control — the weather.
Most of the time, it’s due to a delayed match from the heat or rain.
But occasionally, it’s worse. In 2014, a four-day heatwave saw a record number of players pull out of the tournament. A ball boy collapsed, a player vomited and water bottles melted.
It led to complaints from athletes and spectators alike about management of the sweltering conditions, and transparency around when play was stopped.
The Australian Open made headlines in 2014 after a string of hot days. (AAP: Joe Castro)
A decade on, the grand slam’s approach to dealing with the heat looks different.
It’s changed under the leadership of Carolyn Broderick, who most recently was the Australian Olympic team’s medical director in Paris.
She was appointed as Tennis Australia and the Australian Open’s chief medical officer in 2017 after years of working with professional athletes.
Dr Broderick said updating the heat policy was a major focus, and as a result, co-developed a method to assess the risk of an athlete developing heat stroke in real time.
Carolyn Broderick was appointed chief health officer of the Australian Open in 2017. (Supplied: Australian Open)
As the world faces a future with more extreme heat, she said similar policies should be introduced for all sports.
“Every sport moving forward needs to have a good extreme heat policy that’s based on science,” she said.
“We’ve got to gear up for a warming world.”
Four environmental elements and an algorithm
An athlete under heat stress might experience nausea, dizziness, vomiting and a headache.
And the Australian Open is hot. Every year, there’s at least a few days where the maximum temperature is more than 30 degrees Celsius.
But scientists who research how heat affects the human body are more interested in other weather measurements.
It’s because humidity also has a big role in how hot a person might get. The higher the humidity, the harder it is for the human body to release heat via the evaporation of sweat.
This has led to sporting events, including the Australian Open in the past, to use a metric called the Wet-Bulb Globe Temperature (WGBT) to measure the impact of heat on an athlete.
It’s a weighted temperature value which takes into account dry heat, but also incorporates humidity.
But Ollie Jay, a professor of heat and health from the University of Sydney — who co-developed the Australian Open policy with Dr Broderick — said this measurement did not always capture the full picture.
Ollie Jay co-developed the Australian Open’s heat policy. (Supplied)
Professor Jay said it was established in the 1950s by the US military when training their recruits in the Deep South, where the weather tended to be very humid.
However Melbourne’s summer could also be dry, so that method was not always suited to our climate, he said.
Also, the Open was using an estimated WGBT measurement conducted by the Bureau of Meteorology at a nearby station, so Professor Jay said it was not necessarily reflecting the real conditions at the tennis court.
Instead, Professor Jay’s team devised a new method to not only measure the environmental conditions directly, but to test them on a typical tennis player and estimate their reaction, based on data.
Karolína Muchová of the Czech Republic wipes the sweat from her face in 2021. (AP: Andy Brownbill)
Through research, he selected the four elements that contributed the most to a person’s risk of overheating — air temperature, humidity, wind speed, and radiation from the sun and surrounding objects.
The goal was to measure all of these elements in real time, by the side of the tennis court.
These readings would then be inserted into an algorithm, which estimates how tennis players physiologically react to specific climate conditions — also taking into account the amount of internal heat production, and the clothing they tended to wear.
“So you’ve got six parameters that you need to integrate to figure out exactly what the risk is,” he said.
(Not included in this equation was the surface temperature of the court, because Professor Jay said it did not have a notable impact on body temperature.)
Because nothing was available to adequately measure these elements by the side of the court in 2018, Professor Jay’s team developed their own device, called an environmental management unit, or EMU.
An infographic showing all the features of the EMU. (Supplied: Ollie Jay)
Starting as a homemade contraption, these devices have since been refined into a commercial product.
They have since been used by World Rugby, the Australian Olympic Team, and even music festivals like Beyond the Valley.
Five-point scale promotes transparency
Once measurements from these devices — which sit beside the four major courts and one of the outside courts — are put into the tennis player algorithm, they’re translated into a five-point scale which is presented on a dashboard.
Called the AO Heat Stress Scale, Professor Jay said the system was inspired by the simplicity of New Zealand’s fire danger rating system, where an increasing index indicates increasing risk.
When the index reaches a three, Professor Jay said the climate conditions would be causing moderate stress on the athlete’s body.
At this point, the players would start implementing measures to cool down, like using ice towels.
Once the algorithm has done its calculations, the heat stress scale is shown on a dashboard. (Supplied: Ollie Jay)
Four means the conditions have worsened, and so male athletes would be allowed to take a 10-minute break after the third set, and women between the second and third sets.
And when the scale reached five — the highest point — play would be stopped on the outdoor courts and the roof closed on the indoor courts after an even number of games in a set.
This has only happened about three times in the last seven years.
Professor Jay said the system promoted a gradual implementation of measures to prevent a build-up of heat.
“Theoretically, players can be exposed to hotter conditions for longer while maintaining their health and performance.”
The Australian Open’s heat stress scale ranges from one to five. (Supplied: University of Sydney)
Dr Broderick, the tournament’s chief health officer, said the system was not only easy to understand, but promoted transparency.
“Our policy is based on science, so it’s not at the whim of anyone,” she said.
“[The index] is on every player-facing area, so we have it in the treatment rooms, we’ve got it in the corridors where the players come, we’ve got it in the recovery centre.
“I think bringing [the athletes] along the way has been so important, so they don’t think that it’s sort of secret business.”
Serbia’s Novak Djokovic practices at the Australian Open in 2022. (AP: Mark Baker)
Heat mitigation across the entire tournament
The heat policy starts before the tournament begins.
Dr Broderick said there was a big emphasis on acclimatisation, especially for the players arriving from the wintry northern hemisphere.
“It’s really pleasing to see that a lot of them are coming out here very early now,” she said.
She also said education around reducing heat stress was important, such as encouraging players to have cold showers or ice baths before and after matches.
Organisers have also improved conditions for spectators, including introducing more shade, misting fans, and water fountains.
Organisers have added more misting fans for Australian Open spectators. (AAP: Lukas Coch)
But the policy has not been static. Dr Broderick said they were constantly refining it.
A PM2.5 monitor was added to the environmental monitors after Victoria’s 2020 bushfires, which measures the amount of polluting air particles.
And for this year’s tournament, Dr Broderick said a forecasting feature has been added to the five-point scale.
It meant players could see the predicted heat index rating for their upcoming matches, “so it doesn’t come as a total surprise”.
The EMU sits beside the court to capture the conditions athletes are exposed to. (Supplied: Ollie Jay)
Dr Broderick’s team are also looking to scientifically determine if the policy was reducing heat-related illness at the tournament.
She said they needed to collect another couple of years of data before this research was presented, but hoped the lessons could be extended to other levels of sport and the general public.
For example, some of the most effective measures used by athletes to cool down, such as iced towels, were easy to implement for most people.
“I worry about, with a warming world, not just the impact on professional sport and elite sport, but really what happens to community sport and people’s ability to be physically active,” she said.
“Our other great public health crises are non-communicable diseases from inactivity.”
But so far, Dr Broderick said she believed the policy was working well, as it was easy to understand and took the “subjectivity” out of the equation.
It all serves a greater ambition she has for humans and their health.
Australian player Maddison Inglis cools down with an ice towel in 2022. (AAP: Dean Lewins)
Some of this work includes an online tool she developed with Science Medicine Australia, where anyone can input their sport and geographical location to figure out their heat risk on any given day.
“We’ve got to make it as safe as possible for people to remain physically active in a warming world,” she said.
