Climate change and extreme weather events are threatening the future of sport in Australia, a report warns.
Sports venues and heat policies must improve dramatically to protect the health of athletes at both professional and amateur level, a study by the Climate Institute says.
"The future holds questions around the viability of outdoor summer sport as we know it, and whether major international tournaments should be moved to different seasons of the year," the report says.
Public health expert Dr Liz Hanna said athletes ran the risk of doing serious damage to themselves if they got too hot while exerting their bodies.
"You will end up in a contest of who copes best in the heat more than who is the best in their sport," she told AAP.
"They will be putting their bodies under a lot of strain and the trouble is, the ones who have million-dollar deals won't feel they can pull out as their sponsors won't be happy."
She said the onus should be on organisers to postpone or cancel events if temperatures rose too high.
"The optimal temperature for human physical performance is 11C," she said.
"Once you get up to 21C it really starts to decline."
Increased warming, more extreme heat, changes in rainfall and more intense storms are also putting people off attending outdoor games and tournaments, leading to losses in revenue for venues.
Sport brings about $13 billion a year to the national economy, but events such as the 2014 Australian Open, which had a drop of 12,000 to 15,000 spectators a day due to the heat, will continue to suffer due to climate change, the report warns.
Last year was the world's hottest year on record, and the frequency of extremely hot days in Australia has doubled since 1960, the study says. And days over 35C are set to rise.
Rain is also falling less frequently but in more intense episodes.
Experts are calling for more consistent temperature policies to be applied.
They also want more sporting venues to have features such as retractable roofs as well as equipment and energy efficiencies to compensate for increased cooling costs.
