We have not been able to use fans for the last 6 years, misters were never an option, can not bring genorators, they supplied the large diesel type but with half the needed outlets for a while. You can not guess how many people think you can run 2 blowers off of one 20 amp breaker. We have been blow and go since the drought in the 80's, you can only rinse in the morning between 6 and 9 (public comes in at 10) Safety is their reason they stop it at 9, a pain but makes since after you see how ignorant most people are.
About 5 years ago our fair grounds updated the barns, old barns where from the 40's, they built one big barn to take the place of 4 barns. Granted our fair grounds are on the coast and the outside temp stays around 70 to 75 during the day, but the old barns had low ceilings, with no air flow, it would get up to the 90's inside during the day.
The new barn has the giant dairy ceiling fans in it, once they figured that if they run them all night to cool the barns the temp would stay at 70 to 75 inside during the day. Barns get a little to cool at night forthe Lambs but that's why they have covers. 80 percent of the calves do not have hair anyway, the ones that do seem to do OK after they acclimate over a day or 2
Biggest concern is liability, fans, geneorators, misters require cords, cords equal tripping hazards, tripping hazards equal law suits. Since the fair is for the public that is usually the fairs first concern, exhibitors are there so the fair goers have something to see, plus the state gives them money. If they did not have the youth livestock exhibits, than it would be more of a carnival and not a fair. It is usually all about the money first and safety second.
We have had several of the breeders that come down from up north to watch the shows state they wish the State fair was at our facility, State fair is on the Delta and is usually in the 90's and humid, some years it is in the 100's and 80's at night.