Up to 85,000 people normally attend the show over both days.
Nicholas said: “The vast majority of our exhibitors will still be here, and that is thousands of exhibitors, and we fully understand if there are one or two decisions from exhibitors not to bring their animals.
“We have a no-refund policy for people who have purchased tickets for the show and for whatever reason decide not to come.
“The Royal Norfolk Show is a charitable event and all of the funds raised are reinvested in supporting food, farming and countryside in Norfolk.”
Nicholas said the association had been consulting with a team of vets and animal welfare specialists in order to put precautions in place, and advised people not to bring their pet dogs due to the record-breaking heat.
He also told BBC Radio Norfolk that while the show intended to run all its scheduled classes, some activities could be rescheduled if the conditions were too hot.
Visitors will be able to get free drinking water from standpipes and water taps at all toilet blocks and the show, in partnership with the Big C cancer charity, will be providing free suncream at the main gates.
