Firefighters in part of Yorkshire are being called out at least once a week to help paramedics move obese patients
The union Unison says extreme obesity is a worsening problem, with calls to the fire brigade for assistance increasingly common.
Nationally crews were called out 1,200 times last year, according to official figures, with Kent Fire and Rescue Service dealing with the highest numbers at almost 20 cases a month.
That was followed by Humberside Fire and Rescue Service, which covers Hull, East Yorkshire and Northern Lincolnshire, with 62 cases.
A spokesman for the service said: “Sometimes crews of four or five people may be involved with specialist lifting equipment.
“To bring people safely down some quite tight stairways, if you have a bariatric patient of 20 or 25 stone, two ambulance personnel will not be enough.”
The number of callouts rose 17 per cent last year and was almost triple the 429 cases in 2012-13, when records began.
One in six callouts required 10 or more crew members.
Tam Fry, chairman of the National Obesity Forum, said the failure of successive governments to tackle the country's obesity problem was to blame for the "appalling" figures.
He added: "As the already fat get even fatter expect an even larger number next year.
"Society's main concern must be that crews engaged hauling the morbidly obese from their houses are unavailable to fulfil their principal duty of hauling people from burning buildings.
"If one death should occur as a result it would be a calamity and rightly see the Government disgraced."
A Department of Health and Social Care spokeswoman said: "Tackling obesity is a priority for this government, and we are committed to halving childhood obesity rates by 2030.
"Robust government action has decreased the sugar content in soft drinks by almost a third and we've invested millions promoting physical activity in schools."