Instead of standing in front of a classroom, Lydia Howrilka, 31, has spent the last week on her couch eating soup. She’s tired, aching and has a lingering fever.

“It’s a never-ending disease,” said Howrilka.

She tested negative on her first rapid Covid test and is awaiting results from a second test. But her doctor suspects she has a mild case.

Howrilka is a 10th-grade world history teacher at Clara Barton High School in Prospect Lefferts Garden, Brooklyn, where the desks are six feet apart, students and teachers wear masks and the halls do not bustle.

Clara Barton isn’t in one of Brooklyn’s hot zones but is close enough that many students switched to fully remote instruction out of fear.

“The schools now are like ghost towns,” said Howrilka. “There’s not a lot of energy.”

Howrilka developed symptoms the day that students began their in-person classes on Oct. 1, meaning she didn’t catch it from a student. But teachers were together in school beforehand to get the rooms ready for in-person classes. They had to wear their masks for eight hours a day, “which is really hard.” said Howrilka, who lives in Floral Park, Queens, but has colleagues who live in red zones.

Howrilka thinks she became sick after breathing the same air in the bathroom as an undiagnosed and asymptomatic colleague. They may have both removed their masks for a moment to breathe air.

Howrilka records lectures from her house. She’s taking time off but still provides lessons for her class — substitute teachers are scarce. One of her students, who went fully remote after her parents became too afraid to send her to school, wrote to the principal asking for Howrilka to be allowed to do the same. She was afraid for her teacher’s safety.

On Monday, Howrilka will need to go back to school: The Department of Education only lets teachers take 10 school days off for an illness not diagnosed as Covid. She’s nervous to go back, as she fears she could infect students or colleagues.

Update: Howrilka, still symptomatic, received what her doctor believes to be a false negative on her second test. Her lawyer was able to get her, and 17 others, remote work accommodations.