The Heat Stress Scale (HSS) measures the risk of heat-related illnesses based on environmental factors such as temperature, humidity, wind speed and radiation. For example, the 1-5 scale of the Australian Open (AO-HSS), introduced in 2019, leads to mandatory breaks (4.0) or a game being abandoned (5.0), explains the AI. The 4.0 (high risk) is reached at the Grand Slam spectacle “Down Under” when temperatures climb to 38 degrees Celsius. This is what happened on the seventh day of the “Happy Slam”, when Melbourne Park on the Yarra River was transformed into a real oven.
The air built up, especially in the large stadiums. Like in the Rod Laver Arena, where the two-time defending champion Jannik Sinner played his third round match against Eliot Spizzirri and was in great trouble against the American with the score at 4:6, 6:3 and 1:2. Shaken by cramps, the South Tyrolean sought treatment, but then limped on and conceded the break to make it 1:3. When it looked like the 24-year-old was about to give up, the “heat police” saved the reeling Italian: Level 4.0 was reached on the AO-HSS, the match was interrupted and the roof of the arena was closed.
Jannik Sinner had to seek treatment
© AP/Dar Yasin
For Sinner it was definitely a lifeline that day. The world number two left the court to cool down, returned after the permitted ten minute break, appeared more relaxed, immediately took serve from Spizzirri and ultimately celebrated a 4:6, 6:3, 6:4, 6:4 victory after 3:45 hours. In the press conference that followed, the four-time Grand Slam winner also admitted bluntly: “I was lucky with the heat rule today. I had cramps everywhere. It started with my legs and then it went into my arms. I know that I have to improve in this area,” emphasized Sinner, who had to give up in last year’s Cincinnati final against Carlos Alcaraz when the score was 0:5 due to extreme heat. The accusation in various forums that only the “celebrity bonus” saved the Sexten player is of course nonsense, as the interruption not only affected the Sinner match, but all games on the facility. By the way: The games only stop at level 5.0 – but according to HSS, this is only reached at 46 degrees Celsius.
It is still questionable why Sinner, who will face compatriot Luciano Darderi in the round of 16, always has particularly big problems in hot weather. It is clear that the body loses water and minerals (salts) through heavy sweating and the combination of high physical exertion and high ambient temperature overloads the muscles, which leads to neuronal miscontrol, i.e. cramps. In this context, a look at the weather forecast: Today it is supposed to be a pleasant 24 degrees in Melbourne, on Monday 29, on Tuesday 43 (!), on Wednesday “only” 24 again.
The intense heat is nothing unusual at the Australian Open
© AP/Andy Brownbill
In the evening it cooled down a little in Melbourne – to the delight of Novak Djokovic, who held his own against the Dutchman Botic van de Zandschulp 6:3, 6:4, 7:6 and set several reputation marks with this success: With now 102 victories in Melbourne, he equalized Roger Federer’s record, and with a victory on Monday over the Czech Jakub Mensik he would be the sole record holder. With his 400th match win at a Grand Slam, the 38-year-old Serb also drew level with Federer in terms of round of 16 appearances in Melbourne (18), and he also surpassed the Swiss (69) with his 70th round of 16 appearance in the four major tournaments.
