It's going to be another scorcher in the Chicago area Tuesday, prompting several school officials to cancel classes or end the day early for the second time in just two weeks.

After a muggy Monday with highs in the mid-90s, Tuesday's temps are expected to hit 98 degrees in Chicago with heat indices ranging from 95 to 100 degrees in the metro area.

Despite the simmering heat, Chicago Public Schools remain open Tuesday -- a move that's drawn criticism from those noting many CPS buildings are without air conditioning. Exactly how many? For the record, CPS said last month they don't exactly know.

During the heat-wave two weeks prior, a CPS spokesman sent HuffPost the following on the district's heat protocol:

"In cases where schools do not have air conditioning, principals are following protocols to help keep their schools as comfortable as possible and are utilizing among 800 fans that CPS is making available at their request," while adding, "We are finalizing and updating the total number of schools that do not have air conditioning, but the majority of schools in the district have full or partial A/C in the school."

According to the district's Department of Operations protocol, outdoor temperatures between 85-95 degrees are not considered to be in the "dangerous" range.

A handful of private schools in the city closed or are ending the day early, like St. Francis de Sales High School in the South Deering neighborhood.

In the suburbs, 20 schools kept their doors closed Tuesday over lack of air conditioning. ABC Chicago reports the schools include districts in Waukegan, Naperville, Aurora, Bolingbrook and Plainfield.

Some area parents have pushed to have the school year start later if buildings can't be properly equipped with air conditioning. As the Associated Press reports, "heat days" are becoming almost as common in Midwest schools as snow days.

Both Chicago and Rockford could break high temp records Tuesday. CBS 2 meteorologist Megan Glaros reports 95 degrees is the Sept. 10 record set in 1983.

"The unseasonable hot weather will linger one more day," said the National Weather Service, noting a cold front moving in will cool area temperatures by week's end.

As always, Chicago residents can visit cooling centers at Department of Human Services locations.

Also on HuffPost:

Loading Slideshow...