They also said additional gazebos and parasols had been installed.
Horses are kept cool using misting fans and a mobile water bowser with a 1,000-litre (220-gallon) capacity.
In total, more than 250,000 people are expected to attend the five-day event, which ends on Saturday.
The event was founded by Queen Anne in 1711 and is now well known as a key social occasion, as well as a sporting event.
King Charles, Queen Camilla and the Prince of Wales appeared in a carriage procession at the event on Wednesday – but the Princess of Wales was not in attendance.
