With a top of 39 degrees forecast for Friday, Racing Victoria has changed the Swan Hill meeting to start two hours earlier at 11am in a bid to avoid the hottest part of the day.
The opening race on Saturday's Guineas program is scheduled for 12.25pm with the last of nine races at 5.20pm.
The Group One $1 million Australian Guineas is the eighth race on the program.
“RV will continue to monitor the forecast over the coming days and may adjust race times at Flemington if the forecast temperature does rise,” RV said on Wednesday.
RV's hot weather policy will be in place to ensure the health and wellbeing of horses and participants.
Under the policy, an additional vet is in on hand to assist in monitoring the condition of horses, large containers of ice water are made available at locations around the racecourse and horses spend less time in the pre-race parade.