Boston Public School nurses, along with other members of the Boston Teachers Union, staged a demonstration in front of Boston City Hall Plaza Wednesday, in a show of force that defied a heat wave and the ongoing logistic challenges of gathering large groups amidst the coronavirus pandemic.

The protest comes after the release last week of a “draft” re-opening plan unveiled by BPS Superintendent Brenda Casselius that envisions schools re-opening on a “hybrid” basis, with students going to physical classrooms part-time, with supplemental schooling via online education.

And it comes as Massachusetts has seen a small but potentially worrying uptick in COVID-19 infections in recent weeks.

Members of the BTU, which represents teachers, nurses and other Boston school workers, are calling the draft plan released last week insufficient. They are also accusing Casselius and Mayor Marty Walsh’s administration of failing to include school workers in discussions over re-opening.

Between chants of “All In” and “Safety First,” at least 100 nurses, teachers, and other BTU members said they, too, want to return to school and to the students they serve. But said they have been left out of conversations about how schools can re-open safely for both students and school workers.

They argued they should be more involved in the planning because they are the ones who best understand their schools and their students.

“I feel a sense of duty, to my job, my community, my family, my students, my city,” BPS nurse Ellen McKinney told the crowd.

“I have so much faith in this city. … Now I feel like I don’t anymore,” McKinney added. “We want a seat at the table."

Calling for more funding for — and a more comprehensive plan to provide — rapid testing, McKinney said she worries students and staff are being put in danger.

“When you’re a school nurse, you care about everybody in your building,” McKinney said. “I can see faces coming to my mind as I’m reading the [draft] guidelines. I’m thinking about everybody and wanting them to be safe.”

When asked on Tuesday about the planned protest, Walsh said he welcomed the public action and emphasized that the “draft” plan is just that. N,ow is the time for BTU workers and other school professionals to weigh in, the mayor said.

BTU President Jessica Lang said Boston school workers feel they’ve been left behind, both at the federal level and here in Massachusetts and Boston.

“We are angry. We are angry at the utter failure of the federal government to protect this nation from a pandemic and leaving us in a situation that was completely avoidable,” Tang said. “We are angry because we need guidance and support from our state and local governments as well.”

And angry, Tang said, because BTU members feel their concerns and expertise have been ignored.

“We have said from the start we are here to help, we have ideas, we have solutions, we have expertise and we want to be at the table,” Tang said.

That, Tang said, has not happened.

“We’ve been locked out of the re-opening plan [discussion] that was shared to us one day before going to the school committee,” Tang said. “And we said at that meeting that this plan is not good enough.”

Speaking with WGBH News shortly after the demonstration, Tang said that she and her members intend to take the mayor up on the offer to weigh in, but called the decision to release a draft plan, with what she called minimal input from school workers, irresponsible.