MIDDLESEX, N.J. (CBSNewYork) – Schools officials in New Jersey plan to update parents Monday about carbon dioxide concerns troubling a Middlesex County middle school.

Air quality tests from the state found elevated levels of the potentially toxic gas at Von Mauger Middle School in Middlesex.

Last week, parents told CBS2’s Meg Baker their kids have been complaining about feeling sleepy and sick.

“The district needs to do something. We need to find out why these kids are constantly tired, falling asleep in class. Our testing for this year was very low, the scores were very low. Is this due to the fact that these kids falling asleep?” said Eileen Miller, the parent of a seventh grader.

More: Parents Take Issue With District After Potentially Toxic Gas Found In School

The district was made aware of the elevated levels of CO2 on September 14. Middlesex Borough Schools Superintendent Dr. Linda Madison said the school immediately started opening windows and doors and checked the ventilators.

“What happens in a uni-ventilator is when they are turned on, they pull fresh air from the outside into the room, circulate it, and then it goes back out,” she said. “If the vent is not on, is not operating properly, it’s not pulling enough fresh air into the room.”

The district budgeted to replace the ventilators in a 1950s wing of the school, but Dr. Madison said they ran out of time this summer and will complete the work next year. She said something else will be done in the short-term, before the weather gets cold and the windows close this winter.

Monday night’s meeting will be held at 7 p.m. at Middlesex High School. The superintendent is expected to be there, along with Board of Education officials and public safety experts.