CHICAGO – Students at several Chicago schools are wearing winter hats, coats and mittens in the classroom this week as school officials battle heating problems.

Officials at Inrinsic Charter School on the city’s Northeast Side canceled classes Tuesday after one of three heating units went out Monday. Students were forced to bundle up for part of the day before officials moved them to warmer parts of the building, WGNtv.com reports.

Parents of students at Howe School of Excellence also complained that the heating system wasn’t working correctly, though Chicago Public School officials were unaware of that problem.

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Erica Hill said her three sons reported that the heat was out in several classrooms and a space heater was being used in one, according to the news site.

“It was cold,” said Cordarryl Hill, 11. “It felt like we were outside.”

CPS officials released a statement to WGN about the heating issues, but didn’t address specific problems at specific schools.

“CPS students have returned to classes today from Winter Break, and we have prepared a comprehensive winter weather plan this year to ensure safety for all students, teachers and staff during cold temperatures,” the statement read.

“The District’s maintenance crews have been working over the past week to test all equipment and ensure heating systems are in working order.”

Students on the city’s South Side were also forced to bundle up this week.

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Kendra Taylor, a 10-year-old at W.E.B. DuBois Elementary, told CBS the furnace also broke at her school Tuesday, and the cold became unbearable.

“It’s freezing when try to do my work my hands always get numb,” Taylor said.

Her grandmother was clearly upset about the situation.

“Why would you put child in school for 6 hours with a coat and hat on all day and expect them to function,” she questioned. “Everybody in school including staff walking around with hats, snow pants, gloves, scarves.”

Other parents also complained, although they acknowledged that not all classrooms were without heat.

“It’s cold, they have to have on gloves and hats…somebody needs to do something about it,” parent Linda Redmond told CBS.

“This would not happen on the North Side of Chicago and you know it,” said another parent.

CPS officials said they took care of the issue at DuBois Tuesday.

“This morning, CPS officials quickly addressed a brief heating issue at DuBois Elementary School. The system was repaired earlier today and temperatures were restored to provide a safe and comfortable learning environment in every classroom,” according to the CPS statement cited by CBS.