As 14 bushfires continue to burn in Victoria, the thick haze of smoke isn't just threatening the tennis and hampering evacuations - it could have real effects on people's health.
"Bushfire smoke is hazardous. Often recycling fires are called toxic, but bushfire smoke is also toxic. There are health effects from bushfire smoke that is really the same as any other smoke," said Victoria's chief health officer, Dr Brett Sutton.
Over the last few days, Canberra has had the worst air quality of any city in the world - more than 22 times the hazardous rating.
Melbourne's smoke hasn't just come from Victoria, with much of it being blown in from Tasmanian fires.
Residents have been urged to stay indoors as much as possible, whether they have a condition like asthma or not.
"This morning it was so hard to see, the visibility was so much lower," one local told Newshub.
"I always have my Ventolin on me, especially for stuff like this," said another.
"It was a bit crazy this morning, [it] feels like the fires are right on our doorstep."
Australia's federal government has opened up its stockpiles of P2 masks, although doctors are warning that cloth and surgical masks do little to filter dangerous particles.
"It is important to recognise that masks can give you a false sense of security," Dr Sutton said.
Music festivals have already been cancelled or postponed due to the threat to people's health.
The lingering smoke in Melbourne has also raised concerns over whether the Australian Open tennis tournament, which is less than two weeks away, should proceed.
Men's defending champ and ATP Players Council president, Novak Djokovic, is suggesting it could be postponed. He said he will take air quality considerations to a pre-tournament council meeting.
"The schedule has to be respected in terms of play and Australian Open starts at a certain time so there's a lot of different things involved. But a health concern is a health concern, for me and for anybody," Djokovic said.
Canberra has started to clear on Tuesday, while Melbourne's smoke isn't expected to shift until Thursday - just in time for the extreme weather conditions' forecasted return.