CHICAGO — High temperatures and humidity will bake much of the central U.S. this week, making it feel as hot as 115 degrees in some places and leading some cities to open cooling stations and take other precautions.

The high pressure system, sometimes called a “heat dome,” will push conditions to their hottest point so far this summer, though record hot temperatures are not expected, according to the National Weather Service. Authorities from Minnesota to Louisiana are warning people to take precautions and check on the elderly and other vulnerable neighbors and relatives.

A 4-year-old Illinois girl was hospitalized Tuesday after being found unresponsive in a hot vehicle in a suburb northwest of Chicago. Details on her condition weren’t released. Investigators think the girl climbed into the vehicle without her parents’ knowledge after overhearing conversations about going to her grandmother’s home for dinner, the McHenry County Sheriff’s Office said Wednesday.

In neighboring Missouri, officials blamed heat for the death last week of an elderly woman in St. Louis County.

Excessive heat warnings put out by the weather service were in effect Wednesday for parts of Minnesota, the Dakotas, Nebraska, Iowa, Kansas, Missouri and Illinois.

Heat is the leading cause of weather-related deaths, ahead of flooding, said Andrew Krein, a meterologist with the National Weather Service’s Chicago-area office.