While city spokeswoman Linda LaCloche said she has never seen anyone use Naperville’s Municipal Center as a cooling center, that may change this week as residents brace for temperatures in the high 90s and heat indexes as high as 115 degrees.

The National Weather Service is predicting dangerously hot conditions will move in starting Wednesday morning and continue through Thursday night, officials said.

“We’ve found that generally over the years our community seem to be helping each other, like visiting families, (during periods of extreme weather) more than they come to us for help,” LaCloche said.

Still, the municipal center at 400 S. Eagle St. will be available from 8 a.m. to 5 p.m. for anyone who needs it, she said, as will the city’s 95th Street Library at 3015 Cedar Glade Drive, Nichols Library at 200 W. Jefferson Ave. and Naper Boulevard Library at 2035 S. Naper Blvd. All three will be open from 9 a.m. to 9 p.m.

The city plans to pause all nonessential outdoor work until after the heat wave passes and issued a reminder that anyone who has to be outside take ample breaks, stay hydrated and seek immediate care if experiencing signs of heat exhaustion.

One area that will be affected by the heat is garbage collection. Groot drivers will be starting their routes at 5 a.m., about one hour earlier than normal, on Wednesday, Thursday and Friday.

Among the few people not dreading the heat are those who own air conditioning repair companies, who expect their staffs will be working around the clock dealing with those units that inevitably malfunction during extreme heat.

Kevin Dickson with Energy Services Air Conditioning and Heating Co. in Naperville said most people’s air conditioners will be running nonstop for the next 24 to 72 hours.

“That’s when we see a lot of stress and some of those weaker components break,” Dickson said. “It definitely gets busy for us but this is what we do and our guys like to work. We have a sense of pride during moments like this.”

Like getting an oil change before a long road trip, Dickson recommends people make sure they have a clean filter in their air conditioner before the heat arrives.

Being aware of your physical condition and that of others during excessive heat also is extremely important, local Federal Emergency Management Agency officials said.

“We all need to take precautions,” said Tom Sivak, FEMA Region 5 regional administrator in a statement. “Regularly check yourself and those you care about — especially children, older adults and pets — for the signs and symptoms of heat-related illnesses and be ready to respond to them.”

An excessive heat warning has been issued by the National Weather Service for 11 a.m. Wednesday through 9 p.m. Thursday for much of northern Illinois, including DuPage, Kane, Kendall and Will counties. A high of 97 degrees is expected in Naperville Wednesday and 99 degrees Thursday, but it likely will feel anywhere from 100 to 115 degrees to your body, officials said.

That heat index is the worst part of a heatwave, said Dr. Tom Scaletta, medical director of the emergency services department at Edward Hospital in Naperville.

“It’s not just the heat but also the humidity because when levels are high, the sweat people produce to cool down doesn’t evaporate and the body tends to overheat,” Scaletta said.

Young people and the elderly are particularly vulnerable because they are the least able to regulate their body temperatures, he said.

Residents should stay indoors and move their workouts either inside or to the early morning or late night hours, Scaletta said. Stay hydrated even if you don’t feel thirsty, and if you’re going to be outside, drink products with electrolytes, not alcohol, he said.

Signs of heat exhaustion include weakness, dizziness, a racing heart, muscle cramping, nausea and vomiting. Someone with heat exhaustion should get out of the heat immediately and try to cool themselves down by taking a cold shower or bath, Scaletta said.

mejones@chicagotribune.com

Chicago Tribune reporter Deanese Williams-Harris contributed.