The strong scent from a pumpkin spice air freshener caused the evacuation of a Baltimore high school Thursday when students got a whiff of the mysterious fragrance and became ill.

The heavy aroma — a popular fall addition to lattes and cookies — caused panic among students and teachers at Cristo Rey Jesuit High School, according to the Baltimore Sun.

“It was a smell that they certainly weren’t used to,” the school’s president told the paper. “It appeared to be getting stronger.”

After several students reported difficulty breathing, the principal had the school evacuated and called the fire department — who then requested a HAZMAT team.

The team conducted tests to determine whether there were any hazardous materials in the building, but the tests all came back negative.

After firefighters opened the windows to air out the building, they eventually discovered the source of the offending odor: a pumpkin spice aerosol plug-in inside a third floor classroom.