Dalila Kaupovic was forced to retire from her Australian Open qualifier match on Tuesday after coughing fit. The world No. 180 was a set up in the contest against Switzerland’s Stefanie Voegele when she collapsed on the court due to breathing problems before eventually quitting.

Canada’s Eugenie Bouchard also complained of a sore chest during her qualifying match and needed medical attention before resuming. The twin incidents have put in focus the health-risk the ongoing bushfire smoke pose to the players participating at the Australian Open.

At the Kooyong Classic, Maria Sharapova and Laura Siegemund called off their match due to a combination of smoke and heat. “I started feeling a cough coming toward the end of the second set but I’ve been sick for a few weeks so I thought that had something to do with it,” Sharapova told SBS after the match. “But then I heard Laura speak to the umpire and she said she was struggling with it as well. We were out there for over two hours so from a health standpoint it’s the right call from officials.”

The Australian Open organisers have reiterated that they will postpone matches at the year’s first Grand Slam event if the air quality deteriorates and becomes unsafe for players. “We are treating any suspension of play a bit like a rain delay or a heat delay,” Tennis Australia chief operating officer Tom Larner said on Tuesday. “We will stop if conditions become unsafe based on medical advice and once those conditions are safe to play we will get back on court.”

He added, “We have multiple [air quality measuring] devices across the site and we take into account a number of variables whether it be visibility, particulate matter … there are different levels. Based on those measures we will make a decision, [and] also based on medical advice as to whether we will play or continue play.”