Extra safety measures are being installed in ambulances in Lincolnshire to try to protect emergency workers from attack.
Paramedics are to benefit from 22 new ambulances all fitted with CCTV cameras which start recording only when activated by staff.
Workers can press a strip fitted inside the ambulance during threatening situations and the camera starts up.
It is hoped the new technology will deter people from becoming violent.
Paramedic Adrian Degnan said: "It's there for the protection of staff.
"If a violent incident occurs within an ambulance - and unfortunately it's becoming a little more common - then you can hit a panic strip.
"The camera then starts recording the incident for use in evidence later on."