Together with a colleague, Mr Harrington was assaulted by a stranger while trying to get dinner in a fast food car park in Melbourne's southeast.
It was only days before Christmas when the man confronted the pair, hurling verbal abuse and threats, and ultimately spitting on them.
"It was quite a busy car park, I couldn't go in a hurry. He was smashing on the window, trying to block our exit, and then he tried to jump on the back of the ambulance," he told reporters on Tuesday.
Assaults on paramedics are becoming increasingly common, Ambulance Victoria's metropolitan director regional and clinical operations Vanessa Gorman says.
She describes the escalating violence as shocking, adding that she once had her wrist broken while on the job.
"I've been spat on, kicked, punched multiple times throughout my career," Ms Gorman said.
"I've never seen it as bad as it is now in regards to the severity of assaults taking place, and that includes the sexual assault component."
The organisation said there has been an upward trajectory in occupational assaults this year, with a spike during the festive season.
The issue is not isolated to Victoria, Ms Gorman added.
"While everyone's enjoying Christmas, our staff have endured ridiculous levels of both verbal assault through the use of revolting language, verbal intimidation through to both sexual assaults and physical assault.
"These include cases such as a female paramedic being touched multiple times inappropriately."
Despite the escalating threat, union secretary Danny Hill said paramedics continue to be sent to call-outs alone.
He believes they need more support and should not be expected to respond to jobs solo.
"Not having a partner there with you, (means they) won't be able to help out, look over your shoulder and keep an eye out for any safety concerns," Mr Hill told AAP.
"Occupational violence concerns can be much more dangerous for that single paramedic."
Mr Hill said the number and frequency of assaults had taken a significant toll on the workforce, with many ending up leaving the profession.
"It's not just the physical toll, they can heal from the injuries that they receive when they're assaulted, but there are psychological scars ongoing," he said.
"Some paramedics, when they're assaulted, never make a return to work, and it can really affect their confidence in the job."
Ambulance Victoria metropolitan director of regional and clinical operations Andrew Burns, described situations where paramedics respond alone as a "very complex matter with resourcing".
"Paramedics are never expected to go into a scene that they deem unsafe," he told reporters on Tuesday.
"They will always be supported by Ambulance Victoria with that decision."
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National Sexual Abuse and Redress Support Service 1800 211 028
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