THE AFL's heat policy will be put into effect for the Adelaide v Greater Western Sydney clash on Sunday, with the start time brought forward by five minutes.

Adelaide Oval will host the clash, which will now start at 3.15pm AEDT (2.45pm ACDT).

Half-time has been extended from 20 minutes to 22 minutes, while an extra two minutes have been added on to the quarter-time and three quarter-time breaks.

On Saturday afternoon, the Bureau of Meteorology predicted the temperature would hit 37 degrees.