Firefighters in Vancouver's Downtown Eastside have seen their call volume double due to soaring overdose rates, prompting their union to demand additional resources to fight the crisis.

Fire Hall No. 2, one of the busiest in North America, responded to a record 1,255 calls in November – roughly double the number of the same period last year, according to Vancouver Fire Fighters IAFF Local 18.

The result is a physically and mentally fatigued crew that must resort to reallocating resources from other fire halls to address the critical needs of the Downtown Eastside, potentially putting other communities at risk, said union president Robert Weeks.

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"What we hear from the department is the term 'dynamic deployment,' which really means the stealing of resources from other parts of the city and placing them in the Downtown Eastside," Mr. Weeks said in an interview on Monday. "In our view, that's not a workable solution because then it means a delayed response in those areas that have now lost a rig. In our view, it's not fair that the citizens of Kerrisdale, Kitsilano, Point Grey, for example, have a delayed response to us getting there due to their rig being moved."

The union is asking for – at a minimum – an additional medic unit, which would require 11 full-time staff at a cost of roughly $1.5-million a year.

Mr. Weeks noted that, in the 1980s, Vancouver Fire and Rescue Services would have about 160 front-line firefighters on duty at any time across the city. Today, that number is 132.

"Those kinds of decreases come at a cost," he said. "Vancouver has grown dramatically since the 1980s."

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Vancouver Mayor Gregor Robertson visited the fire hall and went on a ride-along on Nov. 23. Mr. Weeks said the crew felt buoyed by the visit and was left with the impression that more resources would be coming.

However, no meaningful increase has been announced yet. The city's 2017 draft budget has allocated $120-million for VFRS's operating budget, up slightly from $117-million in 2016.

Mr. Robertson was not available for an interview Monday. Sarah Zaharia, a spokeswoman for the mayor, said more information on the budget will be released in the coming days.

More than 622 people in British Columbia have died of illicit drug overdoses so far this year – the highest death toll in more than 30 years of record-keeping. Fentanyl, a powerful synthetic opioid being cut into and made to look like other street drugs, was detected in about 60 per cent of those deaths.

The problem is particularly visible in the Downtown Eastside, which is home to both an open-air drug market and a string of social-service providers.

Firefighters at Fire Hall No. 2 may get 20 calls on a 10-hour shift or 30 on a 14-hour shift.

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Firefighters who spoke with The Globe and Mail in an October feature spoke of the physical and mental toll of repeatedly pulling people back from the brink of an overdose – sometimes the same people, on the same day.

In a statement issued after his ride-along, the mayor called the overdoses crisis "inhumane" and said managing it with first responders is unsustainable.

"Even after months of talking to firefighters, police, outreach workers, drug users and health providers on the front lines of the overdose crisis, and reading countless reports and news stories, it was shocking to see the extreme impacts of fentanyl," Mr. Robertson said.

The city will continue to work with senior levels of government "to quickly deploy resources to support front-line workers and save lives," the Mayor said.

In a separate visit to the fire hall last month, federal Health Minister Jane Philpott said she would "be a strong advocate at the federal level to make sure that we appropriately respond." This includes amending the Respect for Communities Act, a Harper-era piece of legislation that imposed undue barriers to opening new supervised consumption sites.