Police are appealing for witnesses after a Personal Digital Assistant (PDA) was taken from a transport ambulance in Mirfield.
The incident happened on Shill Bank Lane between 5.25pm and 5.35pm on November 18 when staff were helping a patient into his home.
Officers are appealing for anyone offered it for sale to get in contact with police.
David Williams Deputy Director of Operations at Yorkshire Ambulance Service NHS Trust, said:
“Our ability to respond to 999 calls is compromised when thieves break into our emergency vehicles and steal vital equipment.
“The satellite navigation systems we use in the ambulance service are specific to ambulance vehicles and are of no use to members of the public. We also immediately block any mobile phones or hand-held radios that are stolen, so they are useless for making and receiving calls.
“Offenders are putting people’s lives in danger as vehicles are not able to respond to 999 calls if they are damaged or lacking vital equipment.
“This is a problem that we should not have to encounter and we ask thieves to consider their actions and think about how this crime is potentially putting people’s lives at risk. We will always prosecute and seek compensation from anyone causing criminal damage to our vehicles and our equipment.”