Still No Letup in Sweltering Heat : Weather: A record number of fair-goers, however, were not dissuaded by the 90-degree temperatures.

The hot, humid weather plaguing much of Southern California maintained its grip on Orange County Thursday, cooking fair-goers in Costa Mesa and forcing modified summer-school schedules for some schoolchildren.

The mercury hit 91 degrees in Santa Ana, while readings of 94 and 93 degrees were the reported highs in El Toro and Anaheim.

Because of the heat, children attending year-round schools in the Santa Ana Unified School District will be dismissed today 45 minutes earlier than usual--for the second consecutive day--spokeswoman Diane Thomas said yesterday.

Thomas said school officials are unable to make immediate decisions on modified school days because parents must be given 24-hour notice before such an action.

“It’s important to remember that even if a school determines early in the day that it’s going to be extremely hot, we can’t go to a modified schedule on that day because of child-care needs,” she said.

Despite the heat, a record number of people turned out for the Orange County Fair. As of 9 p.m., 26,691 people had streamed through the gates, compared to 21,784 people by the same time last year. A new opening-day attendance mark was set Wednesday as 21,073 people turned out, far exceeding the previous high of 17,608 set at last year’s opening day.

Chad Dugan, who delivers ice twice daily to fair concessionaires, is the one of the main reasons that fair-goers are able to withstand the heat. Based on previous years, he expects to deliver anywhere from 15,000 pounds of ice during the week up to a high of 80,000 pounds of ice on weekends.

“It’s a little hotter than last year,” said the shirtless, 20-year-old as he took a break from his work.

Although humans seemed willing to take their chances in the heat, fair officials took precautions to ensure that fair animals received plenty of water and remained in the shade whenever possible. Other precautions were taken before the fair to ensure the animals’ comfort, according to Jim Bailey, who supervises the Livestock Barn and Centennial Farm.

“Pigs, chickens and rabbits can’t sweat and therefore have the hardest time with the heat,” Bailey said. “We put up extra shade and decided to show the pigs at night. That helps a little.”

Even so, several 4-H Club members monitored their animals’ health closely, with some spraying a mixture of alcohol and water on their pigs, while the animals either slept or sucked greedily on the water spigots placed in the corner of each stall.

With highs reaching into the low- and mid-90s in most of the area, lingering moisture from tropical storm Fausto, downgraded Wednesday from a hurricane, is being blamed for the humid conditions that persist in the area.

“Present conditions are likely to continue at least through the weekend, with a slight chance of showers primarily in the desert and coastal mountain areas during afternoon hours,” said Steve Burback, a meteorologist at WeatherData Inc., a firm that provides forecasts for The Times.