Another western Colorado school is getting a thorough cleaning after a number of its students got sick.

School district spokeswoman Emily Shockley told The Daily Sentinel that about 8% of students at Mount Garfield Middle School in Palisade were sick on Friday.

On Thursday, Palisade High School closed early after 300 students and staff came down with an unknown illness there.

The high school remained closed for cleaning on Friday. Shockley says the middle school will be disinfected over the weekend.

She urged students who feel sick on Monday to stay home to keep the illness from spreading.

Officials haven’t determined what the illness is but Mesa County Health spokeswoman Amanda Mayle said it is behaving like a virus. She the main symptom is acute-onset vomiting.