Illawarra paramedics fear that sending "firefighters with first-aid kits" to emergency callouts will put patients' lives at risk and be emotionally damaging for first responders.
This is one response to the First Responder Program being considered by the NSW government.
Under the proposal, volunteers from the Rural Fire Service and State Emergency Service could be allocated to patients across the Illawarra, and Fire and Rescue NSW officers could respond to medical emergencies.
The Health Services Union (HSU) has slammed the proposed program.
"Only a clinically trained paramedic can arrive at an emergency with the tools and knowledge necessary to keep a suffering patient alive," HSU secretary Gerard Hayes said.
"Sending the fire brigade with a first-aid kit when someone needs an oxygen mask simply will not cut it.
"Our membership have had enough of this and will make their voice heard."
The union will hold rallies across the state next week.
An Illawarra paramedic told the Mercury the plan was already in place in country NSW. Because of a shortage of paramedics, emergency-service volunteers had been "trained in minimal medical assistance skills" to respond and wait with a patient until an ambulance arrived.
"Now they're trying to do that in city areas; they have volunteers, like people in the RFS and SES, who would be willing to do it," the officer said.
The officer said emergency centre operators turned to first responders when paramedics were "not immediately available and already out on other jobs".
"It's to save money, so they don't have to get more ambulance crews."
Another officer expressed concerns for the welfare of the "first responders who have limited experience in major trauma situations".
"Some of their jobs would be major car accidents," he said.
"People are trapped or even deceased. One scene like that and some of these volunteers would never come back.
"It raises all kinds of complications. Do these volunteers write a report on what symptoms they observed before we arrive? Give a detailed description to the hospital staff of how the patient presented? Or do we do that?
"And what about misdiagnosis? We have the depth of knowledge to think on the feet, when someone's symptoms change dramatically and in no time.
"It's too much pressure and it's wrong for someone not trained," he said.
Member for Wollongong Noreen Hay condemned the "blatant disrespect" shown for the skills and dedication of firefighters and paramedics.
She said ongoing pressure on emergency service personnel was "without precedent".
"Firefighters are taught to fight fires. However the first aid training they receive is a far cry from what is needed to deal with a medical emergency," she said.
"They are already being hit with major budget cuts of their own and will now be forced to do more with fewer resources."
Ms Hay said the plan proved the "catastrophic impact of the government's decision to slash $3 billion from the NSW health budget".
Health Minister Jillian Skinner hit back, condemning "attempts to mislead the community about important reforms" to the Ambulance Service of NSW.
"The First Responder Program, which has been operating successfully in 48 locations across NSW, has been in operation since 2005," Mrs Skinner said.
"I want to assure the community that the closest NSW ambulance paramedic will always be dispatched immediately in an emergency.