Dirty air from devastating wildfires could hit matches at the Australian Open tennis tournament.
Officials on Saturday announced they will measure air quality and suspend play if it exceeds 200 micrograms per cubic metre.
Levels between 97 and 200 micrograms per cubic metre will prompt a discussion with medical staff over whether to continue playing.
The move comes despite recent heavy rainfall helping to put out many of the long-running fires. The storms also lead to flash flooding in parts of Victoria. Rain is also announced on Sunday and Monday and is expected to stop some of the few fires still burning.
On Tuesday, one player collapsed in a coughing fit; another sought medical attention for breathing problems.
Australia's recent uncontrollable wildfires have killed more than two-dozen people and millions of animals. They have also destroyed over 10 million hectares of land, the equivalent of Portugal or South Korea.