(CNN) Teachers at Ohio's largest school district voted Sunday to go on strike for better learning and teaching conditions, just days before school is scheduled to start, according to the teachers' union.
The Columbus Education Association union -- which represents more than 4,000 teachers, nurses and other education professionals at the Columbus City Schools district -- is striking for the first time since 1975 after 94% of its members voted to reject the school board's "last, best and final offer," the union said Sunday on Twitter.
Just a day before the vote in Ohio, a union representing about 2,000 School District of Philadelphia employees voted to authorize a strike for higher wages and adequate training programs -- just over one week before school there is set to start.
The strikes come as schools around the country face critical teacher shortages and low morale among educators, exacerbated by the pandemic, low pay and ever more crowded classrooms. Also weighing on teachers are a growing number of school shootings and changing guidance on what educators are allowed to teach.
In Columbus, the union cited class sizes and functional heating and air conditioning in classrooms as examples of points of disagreement with the board, according to Columbus Education Association's notice of intent to strike.
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"We will continue fighting until we have safe, properly maintained and fully resourced schools in every neighborhood," union spokesperson Regina Fuentes said at a news conference Monday.
The Columbus Board of Education called the outcome of the vote "disappointing."
"Tonight's vote by the Columbus Education Association (CEA) is incredibly disappointing. We are saddened by the unfortunate situation our families, our community and, most importantly, our children now face," a statement from the board said.
The board held an emergency meeting Monday that was called into executive session, according to a Facebook Live stream of the meeting. Superintendent Talisa Dixon also released a statement on the strike ahead of the emergency meeting.
"It is my hope that we are able to come to a resolution quickly and get all of our students back in their classrooms with their teachers as soon as possible. It's what our students deserve," Dixon's statement read, which also added the city's recreation and parks department will open nine recreation centers to provide students with "safe, adult-supervised locations and easy internet access."
Speaking about learning conditions in the city's schools, a school library media specialist said temperatures varied wildly from room to room.
"Students move around to different buildings, like a college campus, and they never know from one classroom to the next if it's going to be 50 degrees or 90 degrees," Courtney Johnson told CNN's Victor Blackwell.
Some schools don't have any air conditioning, she said, or may only have "a couple of rooms" with it. And in schools that do have it, including where Johnson works, the systems need fixing, she said.
"That's what we're fighting for -- safe, properly maintained and fully resourced schools where the air conditioning and heating works, and students don't have to suffer," Johnson said.
Columbus City Schools serves 47,000 students, according to the district.
Despite the strike, the school year is still scheduled to begin Wednesday, with classes online and led by substitutes, according to the school district's website.
The district's own administrators may also teach online classes as the strike continues, it said. But since teachers make up most of the district's coaching staff, sports activities may be rescheduled or canceled, according to the website.