Heat wave is coming; it’s time to prepare.

As temperatures soared into the mid-90s, two four-year-old girls, Marlowe Asbury (on left in purple) and Juniper Ozik (on right in pink), found the fountain in Bixler Playlot Park, 1372 E. 57th Street, the perfect spot to cool off. (Photo by Marc Monaghan)

Staff writer

The National Weather Service is projecting high temperatures in the mid- to upper-90s from Thursday through Sunday as a high pressure system settles over the area.

“The upcoming heat wave is the result of an expanding dome of hot air that normally positions itself over the Rocky Mountains and western half of the U.S.,” said Mika Tosca, a climate scientist at the Jet Propulsion Laboratory in Pasadena, California, who teaches at the School of the Art Institute of Chicago. “A change in the jet stream will allow this dome of heat to expand eastward, bringing warm air to the Midwest, the Ohio Valley and the Eastern Seaboard.

“Chicago could hit 100 degrees Thursday through Saturday for the first time since 2012,” Tosca continued. “The heat will be made worse by high dew points, especially here in Illinois. All that corn growing downstate puts a lot of moisture into the atmosphere. When temperatures are as high as they’re going to be, the air can hold a lot of that moisture as vapor. This increases the dew point into the 70s, and, combined with 90-plus degree heat, will push heat indices in Chicagoland into the 100s, possibly 110.”

Melissa Stratton, a spokeswoman for the Chicago Office of Emergency Management (OEMC), reminded people “to take extra precautions and to stay informed about weather-related conditions as temperatures stay in the 90s throughout the week.

“At this time, there are no heat advisories, warnings or watches projected to be in effect for the week,” she said. “However, OEMC will be monitoring conditions throughout the week and is prepared to coordinate resources and responses if conditions warrant.”

The Chicago Department of Family and Support Services advises residents to drink lots of water and to avoid alcohol, coffee, pop and going outside in the extreme heat. Electricity demand will surge during the heat wave, and residents can reduce demand by turning electric lights down or off, which will also help slow warming indoors.

Homes can be kept cooler by minimizing the use of ovens and stoves. People without air conditioning are advised to draw shades and close blinds, but windows must be kept slightly open to allow for air circulation.

People should wear loose, light clothes and take cool baths and showers. Pets should not be left in parked cars, and dogs should be walked in the shade, preferably in the early morning or late evening. If pets or children are locked in a car, call 9-1-1, cover windows to keep vehicles to show the warming and break windows away from the pets or children.

“As temperatures rise, we remind seniors to stay indoors, if possible, and for the public to be aware of the signs and symptoms of heat stroke and heat exhaustion,” Stratton said. Heat stroke is signaled by a body temperature of 103 degrees or higher, dizziness and nausea, throbbing headaches and racing pulses and red, hot and dry skin. Call 9-1-1 immediately to get help for those suffering from heat stroke, move the person to a cool place and give them water.

Lake Michigan’s waters are the mid- to upper-70s and moderate temperatures along the lakefront. 57th Street Beach is open until 7 p.m. daily, and Promontory Point is open until 11 p.m. daily. At press time, there are no swimming restrictions in effect. Do not open fire hydrants.

Check on neighbors, relatives and friends. If unable to make contact, call 3-1-1 to arrange a well-being check.

A municipal cooling center is at the King Center, 4314 S. Cottage Grove Ave. The Chicago Park District will operate cooling centers at both the Jackson Park, 6401 S. Stony Island Ave., and Washington Park, 5531 S. King Dr., fieldhouses. Ald. Leslie Hairston’s (5th) office, 2325 E. 71st St., will also function as a cooling center.

“While it’s not accurate to say that this particular heat wave is ‘caused by global warming,’ these types of prolonged heat events are becoming more and more common in a warming world and could be characteristic of a normal summer by 2050,” Tosca said.