IF YOU CAN'T STAND THE HEAT,...

A once in a century heatwave caused havoc at the Australian Open on Wednesday, forcing tournament organisers to cancel matches and invoke their new Extreme Heat Policy for the first time.

The tournament match referee Wayne McKewen ordered the roof on the Rod Laver centre court be shut and all matches were suspended on the outside courts as the temperature soared past a stifling 43 degrees Celsius.

The players were left soaked in sweat and gasping for air in the sweltering heat while spectators abandoned the stands to watch matches on television sets in shaded bars at Melbourne Park.

The brutal conditions proved too much for the swarms of bogong moths that flutter around the stadium's bright lights, with dozens dropping dead on to the main court.

The Australian Open has always been played in severe conditions but organisers are on high alert this year after the Bureau of Meteorology forecast six consecutive days of 40 degrees temperatures in Melbourne.