Obese patients in Calgary, Alberta, are the first in Canada to have a new ambulance on call specially modified to move them in a dignified and safe way while protecting paramedics from injury.

The so-called "bariatric response team" is called in when the patient weighs between 400 pounds (181 kilograms) and 1,000 pounds (453 kg).

"There's a high risk of injury for our staff... obviously, the larger the patient, the higher the probability is," Paul Lapointe, public education officer at Calgary's emergency medical services, said on Thursday.

"Dignity of the patients was a big thing for us as well."

The ambulance has C$30,000 worth ($27,915) of modifications by a California-based company, including a hydraulic lift.

It also has an air mattress with tiny holes that blow air out causing patients to be lifted slightly off the mattress, making it easier to move them around.

Lapointe says he hopes Calgary's new ambulance will ensure that there will never be shocking images of obese patients being transported by trucks, as in the United States.

"I don't think that's a very dignified way to go but there was no other option in the past," said Lapointe, who once had to create a make-shift ramp for an obese patient.

Statistics Canada says almost one-quarter of Canadians are obese.

"I do have a number of patients who are 500 pounds and up and they normally cannot be transferred anywhere," Dr. David Lau, a University of Calgary endocrinologist and president of Obesity Canada, told the Globe and Mail newspaper.

"It's important to let people know that overweight people are no longer second-class citizens."

Calgary EMS has 16 trained paramedics to work on the new ambulance and four to six of them are needed for each call.

Lapointe said there are no plans to have dispatchers asking 911 callers how much a patient weighs but acknowledged that not knowing could "most definitely" cost time and lives.

"There are a couple of patients that we do have on a reoccurring basis that are about 600 pounds," Lapointe said.