Men's singles players at the Australian Open will be permitted 10-minute breaks if temperatures at next month's Grand Slam reach hazardous levels.
Organisers have unveiled a "more extensive" Extreme Heat Policy after temperatures in the shade approached 40C during the 2018 tournament.
A 10-minute break was already in place for women's and junior singles, plus a 15-minute break for wheelchair singles.
The Australian Open gets under way in Melbourne on 14 January.
Tournament director Craig Tiley said the wellbeing of players was the "utmost priority".
Organisers were forced to defend their heat policy in 2018 after players, including six-time champion Novak Djokovic, criticised their decision not to stop play during extreme temperatures.