Dalila Jakupovic was forced to retire from Australian Open qualifiers because of the "unhealthy" air quality in Melbourne.
She collapsed with a coughing fit and was unable to finish her service game despite leading 6-4 5-6 against Switzerland's Stefanie Vogele.
"I was really scared," Slovenian Dalila Jakupovic told the media. "I never had breathing problems. I actually like heat. But ... I just couldn't breathe anymore and I just fell on the floor."
Former Wimbledon finalist Eugenie Bouchard and Australia's Bernard Tomic also required medical timeout during their games.
A thick haze from the raging wildfires has enveloped Melbourne, leaving air quality in the "very poor" to “hazardous” range.
Meanwhile, Australian Open said it will make further decisions about the matches after consulting with its medical team, the Bureau of Meteorology and scientists from the state’s Environment Protection Authority.
Real Madrid handed shock home loss as Celta Vigo spring surprise
Dubai Capitals overpower Abu Dhabi Knight Riders by 83 runs
Mid East finished strong with victory against Arabia
Norris takes F1 title as Verstappen wins Abu Dhabi race
Neser fires Australia to eight-wicket win in second Ashes test
