Sydney's premier trainer Chris Waller has applauded Racing NSW for transferring the Warwick Farm meeting to Randwick after he witnessed the effect of heat stress first-hand.

The last time a metropolitan meeting was held at Warwick Farm on December 23, in-form gelding Cellarman displayed worrying signs after he won a Benchmark 83 Handicap (1600m).

Waller declared the four-year-old was in the best form of his career ahead of Saturday's Benchmark 85 Handicap (1600m) but admitted Cellarman was taxed by his most recent start.

"Heat stress was noticeable straight after the race so we've monitored him very closely," Waller said on his online stable update.

"It will be interesting to see how he backs up. He seems fine.

"We don't get it (heat stress) much but he puts a lot into his races."

Racing NSW opted to switch to Randwick, which can be subject to sea breezes, after temperatures were tipped to reach 40 degrees at Warwick Farm on race day.

"Well done for getting on the front foot to give the horses a bit more comfort in a lower temperature. The breeze makes a big difference," Waller said.

"You want a horse to run up to its full ability and on a hot day some horses are affected more than others."

He added the effects of racing in hot conditions might only be apparent when the horse races next.

"If they've had a tough race on a hot day, they'll be flat," he said.

"Two weeks later punters will wonder why a horse gets beaten. Normally look back to their last run, see what happened and you'll find they're a bit flat from that race."