Paramedics across the country have been warned to be careful after a second fire aboard an ambulance in a week.
The National Ambulance Service (NAS) is now investigating a possible fault in the 242 model which affects 96 vehicles nationwide, the Irish Mirror reports.
The latest incident relates to a lithium ion battery in the ambulance, but the full details of what happened have not yet been made public.
Last week in Mayo, an ambulance spontaneously set alight while parked near the Sacred Heart Hospital in Castlebar. No crew or patients were in the vehicle at the time.
The NAS informed staff on Friday that it is investigating the cause, suspecting a common fault across all vehicles in its fleet.
A memo circulated to all staff advised using an alternative ambulance rather than the 242 if there is one available.
Senior NAS management informed staff on Friday that a full investigation into a possible fault is now underway.
In a memo circulated to staff they were advised to use an alternative ambulance rather than the 242 if there is one available.
Paramedics have been informed that vehicle auxiliary batteries or the Milwaukee ions may be the cause of the fault.
There were staff reports of some chargers overheating last week - with one crew member saying they had to use a towel to unplug the battery, such was the heat.
It is believed the NAS has 96 ambulances nationwide with lithium ion batteries in the cab.
The NAS told staff: "Following a second vehicle fire today, initial investigation indicates these potentially are auxiliary battery related issues. Investigations and resolutions are currently being worked on and should be ready in the next 18 hours.
"Should crews notice the smell of smoke or fire, evacuate the vehicle ensuring staff and patient safety. Contact NEOC who will notify the fire and emergency services. NAS tactical managers will be working with crews at a local level to advise, support and mitigate risk."
One senior paramedic said: "You couldn't make this up - we are expected to go out there on 999 calls and save lives in ambulances that could be a fire risk.
"If they take the vehicles off the road the whole national ambulance service will be decimated. Hopefully they can get to the bottom of this battery problem as quickly as possible."
The NAS handles on average 1,000 emergency calls a day.
The HSE confirmed two fires had occurred in the two ambulances, and it has identified a technical issue.
It said the first, a recently commissioned Emergency Ambulance was destroyed by fire while parked adjacent to Castlebar Ambulance Station in the early hours of Saturday, June 21, 2025.
A new Community Paramedic Response vehicle awaiting entry to service also went on fire in a vehicle commissioning facility in Tullamore on Thursday. It said neither vehicle was in use at the time, no patients were affected and no staff injured.
The HSE added: "While the two vehicles affected are different makes, models and types, an initial technical examination has identified a possible issue, which is now being urgently explored in further detail with vehicle suppliers.
"In line with health and safety requirements, all staff on duty have also been alerted to the two known incidents, requested to remain vigilant, and reminded of current fire safety, vehicle evacuation, and incident reporting procedures.
"NAS services to the public are unaffected by the current precautionary measures which will remain under constant review."
