Andre Agassi referred to the experience as playing in a “giant kiln”. It’s no surprise, then, that Jim Courier took a plunge in the Yarra after securing back-to-back titles in extreme heat at the Australian Open in 1993. The conditions for tennis in Melbourne in January can be tough – so tough they once left a Canadian player experiencing hallucinations and “seeing Snoopy”.
The tennis circuit has regularly encountered brutal conditions at the Open since it relocated in 1988 from grassy Kooyong up the Yarra to Flinders Park (now Melbourne Park) and its hard courts – and shifted dates from December to January.
When tournament officials contemplated closing the retractable roof for the men’s final in 1993, Courier famously threatened to boycott the match (which he eventually won) because he wanted to play in gruelling conditions.
It took until 1998 before Australian Open officials came up with the first formal extreme heat policy, making the Open the only major tournament in the world to have such a policy.
Basically, an extreme heat policy gives a tournament referee specific medical guidance on when to stipulate extended breaks or when it is simply too hot for players to continue with the stadium roof open.
There have been several versions of heat policies at the Open, most recently the wet-bulb globe temperature readings that became part of folklore, even while the concept was notoriously difficult to understand and explain. This year the Open has moved to a new model developed with the Thermal Ergonomics Laboratory at the University of Sydney. It’s a heat stress scale that monitors four factors – air temperature, radiant heat, humidity and wind speed – and generates advice to players and the public in real time.
So how does it work? And how do players do it – continue to slog through epic matches in furnace-like conditions that would have most of us wilting in moments?
Is the Australian Open the most sweltering slam?
The Australian Open is far from alone in dealing with the impact of extreme heat on players and spectators. Comparing it with other grand slams raises an important point: that temperature, on its own, is not what makes conditions intolerable.
The most recent US Open, for example, was played in a crazily muggy New York spring. In eight of the first 11 days, the maximum temperature was 32 degrees Celsius or more – not necessarily as hot as the hottest days in Melbourne but, critically, humidity was high. The US tournament is played on DecoTurf, which is essentially thick acrylic paint on top of concrete or asphalt. Without a heat policy in place, officials hastily organised one that allowed for a 10-minute break between the third and fourth sets in the men’s draw.
We were naked in the ice bath. It was a magnificent thing.
Serbian star Novak Djokovic later reflected on the novel experience of stripping down and taking adjoining ice baths with his opponent mid-match – during which neither of them were allowed to speak to their teams. “We battled for two-and-a-half hours and then we were naked in the ice bath,” Djokovic said. “It was a magnificent thing.”
Tennis Australia chief medical officer Dr Carolyn Broderick says Australia generates a lot of discussion around heat “because the air temperature can be high, and most people focus on air temperature as the only measurement of heat stress”.
But, she says, “the conditions at the AO are usually associated with low humidity, which aids evaporation of sweat, which is the body’s natural cooling process”.
(It’s not sweating itself but the evaporation of the sweat that has a cooling effect for humans; humidity hinders that evaporation.)
“At the US Open, the air temperature was lower than we can experience here but because of high humidity and low wind speed it was difficult for players to ‘shed’ heat.”
It makes sense, then, that Australia’s Samantha Stosur described last year’s US Open as “way worse” than any Australian Open.
Associate Professor Ollie Jay, who is director of the Thermal Ergnomics Laboratory at the University of Sydney, has simulated conditions at both the US Open (36 degrees Celsius and 55 per cent humidity) and the Australian Open (44 degrees and six per cent humidity). “Participants did far worse in US Open conditions,” he says.
Even staid old Wimbledon can get a tad balmy, even though the grass courts are kinder to players in the heat. The hottest day at the All England Lawn Tennis and Croquet Club was about 35 degrees in 2015.
As for the grand slam event played on clay, well, conditions are pretty reasonable for the French Open – as it should be for an event played in Paris in the springtime.
But in Melbourne, the 2008 switch from Rebound Ace to Plexicushion – a hard court surface made with a blend of latex, rubber and plastic particles meant conditions continued to be hot under foot. And, plainly, playing at the peak of summer creates a likelihood of hot weather.
Where it gets extreme is in years such as 2014, when a severe hot spell – four days of between 41.5 and 43.9 degrees Celsius – resulted in the implementation of the extreme heat policy. A ball boy fainted, almost 1000 fans were treated for heat exhaustion, some players reported that their shoes and water bottles were beginning to melt and numerous players withdrew during the second round.
Last year Djokovic and Frenchman Gael Monfils slugged it out in the second round in temperatures that peaked at 39 degrees. Monfils, in particular, experienced dizziness, tiredness and shortness of breath and told a doctor on court he feared he was going to collapse mid-match. Likewise, France’s Alize Cornet got dizzy and slumped to the court as the temperature edged past 40 the following day.
Heat proofing: how players prepare
It takes 10 consecutive days of training in hot weather to become “heat acclimatised”, says Associate Professor Jay, who is an expert in thermo-regulatory physiology.
One of the issues for players is the timing of the Open, coming so early in the new year after a period of “time off” through Christmas. To help players prepare and adjust, there are valuable lead-up tournaments in Perth, Brisbane, Sydney and the Middle East. Experienced players constantly tinker with their program but most expose themselves to at least one serious tournament in Australia before competing in the opening major.
Heat acclimatising isn’t just about developing psychological grit; it offers physiological rewards.
Through heat training, the athlete’s body develops adaptations that allow it to be more resilient.
It helps players sweat more, says Associate Professor Jay. It also reduces their resting body temperature slightly so they have more of a buffer before they get to critically high temperatures. (With the human body’s resting core temperature being 37 degrees Celsius, every degree up or down has a significant impact. A core body temperature of 40 degrees is a big jump for a human and the point at which heat exhaustion can set in.)
Heat training can also reduce the amount of work an athlete’s heart has to do for any given amount of physical activity because the training increases the amount of plasma in the blood, which improves cardiovascular capacity.
What’s more, the athlete’s body develops adaptations that allow it to be more resilient. Heat training can increase levels of heat shock proteins in the body, for example, which help facilitate cell recovery and limit damage.
A recent study of elite cyclists competing in the Middle East reported core temperatures as high as 41.5 degrees, says Associate Professor Jay, indicating just how resilient these adaptations can make an athlete.
Ice, ice, baby: what really works to keep cool?
Asked about her heat-coping strategies in New York last year, Caroline Wozniacki said, “I just tried to cool down between games, used ice. I’m just thinking I’m on the beach, I have a margarita in hand, life is good.”
Visualising cocktails may not have been one of the strategies put to the test by Associate Professor Jay but he has assessed various other cooling methods in conditions simulating those of the Australian Open.
What worked “really well” was damp towels filled with three kilograms of crushed ice and placed around the neck – as well as a damp towel across the lap and one over the head.
“Cooling strategies” will kick in at the Australian Open when the heat stress scale reaches level three or above – and science shows that players should get in early. Associate Professor Jay found that measures such as ice towels work best when used “right from the get-go” in a match and “at every opportunity” rather than just when an athlete starts feeling hot. In other words, they have a cumulative effect, reducing the rise in core body temperature by about .5 degrees Celsius.
You can do something that makes you feel cool but it doesn’t cool you down.
Air fans also work when blowing on wet skin – the breeze helps sweat evaporate. Using a fan on its own, without dampening the skin, actually makes things worse – it simply adds extra heat to the body. Misting fans, which are provided for patrons at the Australian Open, also got the tick in the laboratory.
While it’s important for players to stay hydrated, the temperature of the water doesn’t have a measurable cooling effect, Associate Professor Jay found. And drinking ice slushies before a match might make players feel better, and will reduce their body temperature a little bit, “but the effects are transient”.
“You can do something that makes you feel cool but it doesn’t cool you down,” he says. “Skin sensors pick up a feeling of coolness independent of how hot you actually are deep in the body, which is what matters when it comes to heat-related illnesses.”
In some ways, players are lucky their sport affords them time to cool down. As Dr Broderick points out, “Unlike many other sports, tennis players have a 90-second break after every two games, in which they can implement cooling strategies such as hydration, ice towels and sitting in the shade. In many other sports, where there’s not this same opportunity for cooling breaks, metabolic heat production is likely to be higher and the ability to cool is less.”
‘Unholy temperature’: what players say
“I like the surface, the venue – the heat,” wrote Andre Agassi in his autobiography Open. “Having grown up in Vegas, I don’t feel the heat the way the other players do, and the defining characteristic of the Australian Open is the unholy temperature.
“Just as cigar and pipe smoke lingers in the memory after playing Roland Garros, the hazy memory of playing in a giant kiln stays with you for weeks after you leave Melbourne.”
Andy Murray had a different take. “When I went out to hit before my match in mid-afternoon they were very tough conditions,” he said in Australia in 2014. “Anyone would struggle in that. You’ve got to be very careful, there have been some issues in other sports with heart attacks. In this sport, when you’re really pushing your limits you don’t want to see anything bad happen.”
It was good for what I wanted to do on court. I needed fast condition. I didn’t want to run.
And Djokovic, after his match last year against Monfils, said, “People might say at this level you have to be, as a professional tennis player, fit. It’s the beginning of the season, you work and train hard to be able to sustain these kinds of conditions and be tough, but I think there is a limit and there is a level of tolerance between being fit and being in danger in terms of health.”
Yet for some players, handling arduous conditions – especially for hours at a time – is a badge of honour, a sign that seemingly doing the extra yards in training will pay off down the track.
“It was good for what I wanted to do on court,” said France’s Gilles Simon after a five-set marathon during the 2014 heatwave. “I needed fast condition. I didn’t want to run.”
Some players also cite surviving searing conditions as a test of mental strength.
“It’s just a mental thing,” said Swiss maestro Roger Federer after beating Australia’s James Duckworth during the same heatwave in 2014. “If you’ve trained hard enough your entire life or the last few weeks and you believe you can do it and come through it, there’s no reason. If you can’t deal with it, you throw in the towel.”
How will organisers deal with the heat?
Under the Open’s new heat policy, category five is the danger zone when, as Dr Broderick puts it, “the risk of heat-related illness significantly increases”. Play will be suspended, allowing for the retractable roofs to be closed on the three main courts. A 10-minute break between the third and fourth sets is new for men’s tennis in 2019. (Women’s tennis already had an extended break between the second and third sets under previous heat policies.)
Dr Broderick says the algorithm behind the 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.
“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 [including from surfaces such as the ground] or the strength of the sun, humidity and wind speed.”
One of the first things we did was to do an overlay of decisions that we’ve made over the past five years …
This means an air temperature reading of 40 degrees won’t necessarily mean the heat policy comes into play. Players will be sweating profusely in that temperature range, but, crucially, the conditions must be safe enough for that sweat to also evaporate and maintain core temperatures at the right level. Humidity is the big factor.
“If we have 40 degrees,” says Tennis Australia chief operating officer Tom Larner, “but low humidity, high wind, cloudy conditions, it may be that play continues – but if we have 40 degrees with high humidity and no wind and sunshine, it’s likely under that scenario that we would hit [a score of] five [and play would be suspended].”
Reflected radiation from surfaces such as the court will be measured as a “black globe” temperature.
Tournament director Craig Tiley says the new scale, generated from five different “weather stations” across Melbourne Park, will provide better data in real time and give players predictability so they can “put their own strategies [about dealing with the heat] in place”.
Meanwhile, officials have concluded that previous decisions about implementing or not implementing the extreme heat policy at times of oppressive heat would have been backed up by the new scale.
Says Tiley: “One of the first things we did on the outcome of that data was to do an overlay of decisions that we’ve made over the past five years. It was aligned to all the decisions we made were correct under this new policy.
“Our decisions would have been correct.”