It's shaping up to be a hot weekend in Sydney, prompting Racing NSW stewards to implement several measures to help horses and jockeys cope with the extreme conditions.

The Bureau of Meteorology is predicting temperatures of 37 degrees at Warwick Farm and 41 degrees at Richmond.

In order to minimise the risk of heat stress and dehydration to horses and riders on Saturday, Racing NSW steward Ray Livingstone says the pre-race parade time will be reduced.

Stewards will also permit a delayed arrival time for horses on course to an hour before the race.

"Instead of 15 minutes in parade we might halve that time to seven or eight minutes for horses," Livingstone told AAP.

"We've still got to get them to the barriers in time with their riders."

The Racing NSW riding in hot weather policy states that most horses easily adjust to conditions of high heat and humidity.

"In general, thoroughbred races are conducted over relatively short distances, so maximal exertion in the heat only occurs for a short period," the policy reads.

Air-conditioned swab boxes, extra vets and swab officials, and buckets of ice water will be on hand if required, Livingstone said.

"This means the horses and riders are out there for the minimum of time in the elements," he said.

"If the horses are distressed we can get assistance to them quickly and appropriately."

Livingstone can recall only two days during his career when race meetings were cancelled due to heat - once at Scone when the temperature reached 44 degrees, and once at Hawksbury when it hit 45.