MELBOURNE: The Australian Open tennis Grand Slam starts next week in the midst of a bushfire crisis that has left at least 27 people dead and destroyed more than 2,000 homes.
Toxic air pollution clouded Melbourne on Tuesday, halting practice sessions and slightly delaying qualifying.
AFP Sport looks at the implications for players and fans at the first Major tennis tournament of the year, which starts on Monday:
What are the dangers?
Air pollution could pose health problems for players, fans and officials, especially in the high temperatures of the Australian summer.
Until Tuesday, Melbourne hadn't been as badly affected as Canberra or Sydney, but conditions deteriorated suddenly.
Air pollution shot up to "hazardous" levels, city authorities said, telling residents to stay indoors and keep pets inside.
Australian Open practice was suspended and qualifying delayed. Slovenian qualifier Dalila Jakupovic had to retire from her match after suffering a coughing fit, although it wasn't clear if pollution was to blame.
However, Tennis Australia chief Craig Tiley has said he expects the tournament to go ahead as scheduled.
"We don't expect any delays and we've implemented additional measures to ensure the Australian Open will be able to run as scheduled," Tiley said last week.
How bad can it get?
Fires are still burning in Victoria, where Melbourne is the state capital, and could continue throughout the tournament, with huge blazes to the city's east.
"It is going to depend on the prevailing winds and whether we have ongoing fires," Christine Jenkins, professor of respiratory medicine at the University of New South Wales in Sydney, told AFP.
"It's still an open question just whether or not we could still have further periods of intense pollution."
On Tuesday, air quality monitors recorded pollution at 20 times greater than safe levels in some parts of Melbourne.
"There is very definitely the threat of fire that could cause significant air pollution in Melbourne," Jenkins said.
What are the health risks?
Players who are recovering from respiratory tract infections are particularly at risk, as well as those with asthma.
Pollution can irritate the respiratory tract, intensifying and prolonging symptoms -- but the health dangers don't stop there.
"It (pollution) increases the risks of respiratory symptoms, cardiovascular disorder, eye symptoms, or mental disorders," warned Professor Yuming Guo, head of the Climate, Air Quality Research Unit at the School of Public Health and Preventive Medicine at Monash University in Melbourne.
"All these would influence of the performance of the players."
What's being done for players?
Meteorological and air quality experts will be on site to monitor conditions. Any smoke hazards will be treated in a similar way to extreme heat and rain, with umpires able to stop play if air monitoring shows it is too dangerous to continue.
Melbourne Park, the venue for the Australian Open, has three roofed stadiums and eight other indoor courts. While facemasks are impractical for players, Jenkins advised them to stay hydrated and get plenty of rest.
"Staying well hydrated keeps the respiratory membranes well moistened and less prone to irritative symptoms," she said.
"Avoiding alcohol, getting plenty of rest, sleeping normal hours and not being outdoors any more than you need to be. Difficult for players, because they're on practice courts and they're constantly trying to keep their (practice) hours up."
Have the fires affected other events?
Last month's SOLAS Big Boat Challenge in Sydney was cancelled after thick smoke from bushfires sent visibility plunging on Sydney Harbour. A Big Bash cricket match in Canberra was also scrapped because of poor air quality and visibility.
At the Australian Open golf tournament in Sydney last month, players complained of stinging eyes. and 2015 champion Matt Jones said conditions were some of the worse he had ever encountered. In November, Rally Australia, the last leg of the FIA World Rally Championship, was cancelled.
But most sports fixtures have gone ahead. Australia played cricket Test matches against New Zealand in Melbourne and Sydney. And the 10-day the ATP Cup tennis tournament has proceeded in Sydney, Brisbane and Perth without serious problems.
Could the Australian Open be cancelled?
Unlikely. Even if air pollution remains high, organisers would be reluctant to axe what is perhaps Australia's biggest sports event of the year, and one of only four Grand Slam tournaments on the tennis calendar.
According to The Australian newspaper, they will be well covered if they do: an insurance policy will provide a hefty pay-out stretching into nine figures in the event of a cancellation due to extreme weather.
However, at least one health expert would support delaying or axing the tournament altogether if air quality remains low.
"If the air pollution is still serious, it would be better to postpone or cancel it," said Guo.
"People when playing or exercising are more affected by air pollution, because they inhale deeply forcing air into their lower respiratory system where air pollutants accumulate with prolonged exposure."