The suspension of the Australian Tennis Open in Melbourne following two days of soaring will cause severe disruption to in ad schedule of 32 singles matches as well as doubles.
The Australian Open extreme heat policy has been implemented," said a statement.
The roof on Rod Laver Arena and Hisense Arena will be closed at the end of the set. Play will be suspended at the end of the set on all outside courts until further notice.
Temperatures could go as high as 44C according to forecast and remain high on Friday.
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As temperatures climb through the day, the warmest spots are likely to be across western parts of Northern Ireland and western Scotland.