Thieves who stole satellite navigation systems from ambulances in Leicestershire are putting lives at risk, health officials said.
The devices were taken from three vehicles in the past week.
Hundreds of pounds of damage was caused to the ambulances, which have had to be taken off the road for repairs.
Officials said the sat navs would only work in the ambulances and the equipment would be worthless when removed from the vehicles.
In one case, the crew also had clothing and personal equipment stolen from an ambulance.
Ambulance service spokesman Phil Morris said: "Each time one of these units is ripped from the dashboard, several hundred pounds of damage is caused.
"This alone is very annoying, but more importantly, whenever a theft occurs, we have to take the vehicle off the road until replacement equipment is fitted and so the ambulance is out of action."