United Fire Brigades Association (UFBA) chief executiveBill Butzbach said while there was no complex data on the frequency of assaults on volunteer firefighters, anecdotally it exists.
Firefighters encountered verbal threats of harm all the way to a - less frequent but more serious - physical fracas.
How often assaults occurred was "likely to be much higher" than the attention-grabbing severe incidents portrayed.
"Assaults on emergency services personnel by members of the public, while attending an incident, is a deeply upsetting risk that responders face," Butzbach said.
"The wide range of incidents that firefighters respond to also increases their risk of exposure to situations where abuse, threats of violence or assault from a member of the public may occur."
Vehicle crashes and medicals were the most likely scenario where volunteer firefighters would face the risks of assault or threats.
"These emergencies expectedly come with highly intense emotions as the patient, the whānau, bystanders and the firefighters are exposed to significant stress and trauma," Butzbach said.
"Additionally, sometimes there is the added risk of persons present being under the influence of drugs and or alcohol."
Verbal threats and violence would "undoubtedly" contribute to any firefighter's post-traumatic stress, Butzbach said.
In a bid to keep themselves safe in sometimes "highly volatile and unsafe" environments, firefighters had to maintain a keen awareness of their surroundings and anticipate "stress reactions".
"...and possess a confident level of de-escalation skills," Butzbach said.
Fire and Emergency New Zealand - Northland group manager Graeme Quensell described assaults on Northland career firefighters as "uncommon".
"But even one confrontation is one too many," he said.
"For any first responder or emergency service personnel to experience such behaviour attending an emergency is extremely disappointing."
On the medical side of emergency responses, ambulance officers and 111 call handlers bore the brunt of unpredictable or violent patients.
St John Mid North territory manager Wally Mitchell said despite their strong commitment to patient care, staff came first.
"St John has a zero-tolerance policy towards abuse or assaults on our staff.
"Our people come to work to make a difference to the lives of New Zealanders, not to be threatened, abused or assaulted."
St John personnel have extensive training and support to prevent and mitigate abuse and assaults, Mitchell said.
In addition, the clinical communications centres assist frontline staff with identifying high-risk addresses; arranging for police to attend before paramedics; and completing regular welfare checks on crews.
However, Mitchell acknowledged it was "almost impossible" to "completely guard against violent and unpredictable behaviour".
"We ask people to please be kind to our staff," Mitchell urged.
"Our ambulance officers and call handlers are caring, non-judgmental professionals who are here to help all New Zealanders.
"They have a right to feel safe at work."
In the event that a St John employee or volunteer was assaulted, the organisation has a magnitude of support systems available.
"We also have a registered psychologist who leads a team to directly support staff and assist with an organisational mental health and wellbeing support framework," Mitchell said.
Both emergency services appealed to their staff or volunteers to report assaults.