Montrose High School was scrubbed down over the weekend after a student was diagnosed with an antibiotic-resistant staph infection.
School district spokeswoman Linda Gann says health officials told educators that scrubbing down the building wasn't necessary.
But they decided to go ahead because custodians do that kind of cleaning every year anyway.
School officials learned last week that a student had been diagnosed with the infection.
Gann says students were already scheduled to be off Thursday afternoon and Friday.
The school has about 12-hundred students.
It's expected to reopen Monday on a regular schedule Monday.