"If someone takes something they think they can sell, it impacts on us. Even if it's something as simple as a Navman, that can have a huge impact on how long we can get to a job. It can have life-threatening consequences if the driver is not familiar with the area."
The bag was found nearby by a member of the public and returned to St John on Sunday.
Mrs MorrishAllen said the bag had been rifled through but luckily the uniforms hadn't been damaged and could be returned to the ambulance.
"Even uniforms are expensive and paid for by donations," she said. Drugs were not accessible to the public and it was the ambulance officers' personal belongings that tended to be targeted.
"People go into the kit bags to look for wallets, cash cards and electrical goods, such as iPhones and iPods."
In February 2011 a specialised emergency kit containing life-saving drugs and other equipment was stolen from an ambulance while paramedics helped a patient in a Mourea home. In September 2010 a $36,000 defibrillator was stolen while paramedics were treating a drunk teenager at a party on Vaughan Rd. Two oxygen gas bottles were also stolen.
Rotorua police Inspector Ed Van Den Broek said emergency service workers were there to help the public.
"Whether it's St John, fire or police, we're here for whatever the emergency situation is. It's pretty stressing for the emergency services to have their vehicles interfered with when they're working with the public."