Ambulance staff in the East Midlands have said special vehicles to deal with patients who weigh up to 55 stone (349 kg) are proving invaluable.
Larger patients used to be moved with help from the fire service
The four bariatric ambulances, which cost £100,000 each, have greater capacity, hydraulic hoists, additional suspension and a larger stretcher.
The ambulance service said an increase in patients' weight had made the new vehicle an important resource.
New vehicles would all be designed to handle bigger casualties, it added.
Standard ambulances can currently only cope with people up to about 30 stone but a steady increase in the size of the largest people meant this was no longer sufficient.
Terry Doherty from the East Midlands Ambulance Service said larger patients had previously been subject to ad-hoc solutions.
"We would get the help of the fire service to load the patient on to canvas and basically manhandle them on to the back of the vehicle, because we couldn't get them onto stretchers."
He added: "This is better for the crews involved and it is much more dignified for the patient.
"It is also safer for the patient and it is safer for everybody concerned because it is the right equipment to deal with the task."
Four of the vehicles are in service in Nottingham, Lincoln, Leicester and Derby with a fifth ordered for Northampton.