Students at a Baltimore high school had gotten a whiff of something weird.

During class Thursday afternoon, students at Cristo Rey Jesuit High School started to smell a “strange odor.”

Some of them began to cough and have trouble breathing, so students and staff members were evacuated from the building, and the fire department was called to investigate the cause.

“Emergency medical technicians evaluated several staff members and students, some of whom were treated on the scene,” the school said in a statement. “Five members of our community were transported to area hospitals as a precautionary measure.”

Cristo Rey Jesuit High President Bill Heiser said, at first, some thought the smell was from a burned out lightbulb.

“It was a smell that they certainly weren’t used to,” he told the Baltimore Sun. “It appeared to be getting stronger.”

As it turned out, the strange odor was coming from a common seasonal source: It was “this plug-in air freshener that basically puts out the odor every so many seconds, and it’s pumpkin spice,” Baltimore Fire Chief Roman Clark told NBC affiliate WBAL.

The fire department sent a Hazmat team to test for hazardous materials, but Clark said the readings throughout the high school were negative.

Still, the chief said, it’s always better to be safe.

“Let us, who are the experts, come in and make sure that everything is safe,” he told WBAL. “We have no problem with them making this call.”

The bad news: Classes will resume Friday.

The good news: It may still smell like fall.

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