(CNN) Rebecca Field is furious. She didn't sign up for this.

The Richmond, Virginia, teacher signed up to teach art history -- not, as she says, to "be ripped apart by a spray of bullets that came from a semi-automatic rifle."

Make no mistake, she'd give her life to save her students. But she resents that we live in a time when that's a choice teachers now have to make.

So Field wrote an open letter to elected officials; a powerful letter where she pours out her heart about the way things are, and her frustration at why they are this way:

At the end of my teaching contract, it says that I will perform 'other duties to be assigned.' I do not interpret these words 'as bleeding to death on the floor of my classroom.'

A responsibility too great

Scott Beigel

Field told CNN she was compelled to write the letter, and post it on Medium, after she read about Scott Beigel, a geography teacher at Marjory Stoneman Douglas High School who was shot and killed as he held the door open for students to escape.

I imagine that if someone was trying to kill my students, that I would try to save them with all my being. I probably would jump on top of a child to save her life. And yes, I might be one of those heroic teachers that the media writes tributes to after their death.

But she adds:

Instead of making dead teachers into saints, make them safer when they are still alive.

There are many things that irk her. Teachers are already underpaid and overworked. They are tasked with the awesome task of raising the next generation of responsible Americans. And they do it gladly.

"When you read these articles, you see these people as heroes. But we never signed up or volunteered to die," she told CNN.

She says she's terrified of the responsibility she and others like her are being asked to accept -- a responsibility "far greater than I can rationally accept."

On Back to School Night, I look out at the gazes of the parents in front of me as we silently make a pact. "I am giving you the most precious part of me with the knowledge that you will shield my child's body with your own when the need arises." They say this with their eyes. I agree to this responsibility and make a silent unbreakable oath before them.

As I am telling them about the 20,000 years of global art history that I will be teaching their child, I am also agreeing to die.

A choice too difficult

She shouldn't have to make such a choice, Field said -- especially since it means choosing between being a teacher and a parent. If she gives her life for her students, she robs her children of their mother.

How dare you force me to choose between my own children and those that I teach. How dare you allow powerful adults who love guns to be more important than a generation of children growing up in fear. I don't want to spend mornings memorizing my children's clothing so I can identify them later.

The September 11, 2001, attacks occurred during her first year of teaching. The safety drills have become more intense.

"A shooting at work is something that is always in the back of my mind," she said. "But as a parent I worry more about my children -- the fear that something might happen to them, or how will they grow up without me in their lives."

A solution too elusive

Field wrote the letter last week. This week brought President Trump's suggestion that one way to ensure school safety is to arm teachers.

How would that even work, Field asked?

"I have to worry about my purse getting stolen, will I have to worry about a gun getting stolen too?," she told CNN.

She said that officers are taught to fire their weapon when they feel their life may be in danger.

"That's why when kids come out, they come out with their hands up. How would police know who to shoot at if everyone has a gun?"

What's most frustrating to her is that there are so many other solutions, Field said.

"We need to hire more teachers, more counselors, more social workers to keep closer attention to students "

She has a classroom of 30 students. Help reduce class size to 20 kids and she can keep closer attention on them.

That, however, hasn't happened. So this is the reality teachers like her live with.

How dare you make me into a hero when I just want to teach.

The full text of the letter

Dear every elected official,

Nowhere in my contract does it state that if the need arises, I have to shield students from gunfire with my own body. If it did, I wouldn't have signed it. I love my job. I love my students. I am also a mother with 2 amazing daughters. I am a wife of a wonderful man. I have a dog that I adore. I don't want to die defending other people's children; I want to teach kindness and responsibility...and Art History. That's what I am supposed to do each day. Blocking bullets? I am not supposed to do that. I imagine that if someone was trying to kill my students, that I would try to save them with all my being. I probably would jump on top of a child to save her life. And yes, I might be one of those heroic teachers that the media writes tributes to after their death. But I am furious that I would have to make this sacrifice. I am incensed that my own children would lose their mother because I chose to be a teacher.

I chose to be a teacher knowing that on most days I would not be able to use the bathroom until 4 pm. I chose teaching knowing that I would be grading papers all weekend and working far beyond the hours of my contract. I chose to teach even though it meant that I would miss every awards assembly and field trip that my daughters asked me to attend. I even signed up to sit in a counselor's office with a teenager on my lap, holding her as she sobbed through an anxiety attack. I signed up to ask a child if they were considering committing suicide and then relaying this terrifying information to a parent. It seems like a lot to agree to, but truly I knew what I was getting into.

I did not sign up to be ripped apart by a spray of bullets that came from a semi-automatic rifle. At the end of my teaching contract, it says that I will perform "other duties to be assigned". I do not interpret these words "as bleeding to death on the floor of my classroom". The anger that courses through my body after a school shooting in this country is accompanied by pure panic. I am terrified of my own children dying in school, first and foremost, but I am also terrified that the responsibility that sits on my shoulders as a teacher is far greater than I can rationally accept. On Back to School Night, I look out at the gazes of the parents in front of me as we silently make a pact. "I am giving you the most precious part of me with the knowledge that you will shield my child's body with your own when the need arises." They say this with their eyes. I agree to this responsibility and make a silent unbreakable oath before them. As I am telling them about the 20,000 years of global art history that I will be teaching their child, I am also agreeing to die. When I am in the parent's place at my daughter's school, I am asking the same of her teacher. This teacher may end up being the only thing blocking a bullet aimed for my daughter's head.

I am furious. How dare you force me to choose between my own children and those that I teach. How dare you allow powerful adults who love guns to be more important than a generation of children growing up in fear. I don't want to spend mornings memorizing my children's clothing so I can identify them later. I don't want to spend professional development hours learning how to save a few more lives by setting up barricades. Sometimes when a kid is driving me crazy in class I think to myself: "Would I die for you? Would I lose everything to save you from harm?" I have my moments when I shake my head NO.

Instead of making dead teachers into saints, make them safer when they are still alive. Make it possible for schools to have smaller class sizes so that we can get to know our students and look out for the ones who need help. Hire more counselors and school nurses and social workers and psychologists so that many people are caring for each child. HELP us prevent this. Take away guns from people who will murder us. Stop taking money from the NRA and proving how soulless you are. Keep us safe so I can do my job. How dare you put me into constant danger so that you can be reelected. How dare you make me choose between saving children or making my own children motherless. How dare you make me into a hero when I just want to teach.

By Rebecca Berlin Field