A family of four nearly died while crossing the border into Canada. Such episodes will likely increase.

These were migrants, presumably crossing the northern border in search of a better life. But, upending the usual narrative, they were heading north, not south — fleeing the United States for Canada. After they were brought to a local hospital to be treated for severe hypothermia, Pillarova said, they were arrested and requested refugee status.

The debate over illegal immigration in the US in recent years has focused on those seeking to enter the country. But President Trump’s vow to deport millions of those already here has Canadian authorities bracing for a spike in dangerous crossings from the south, like the one that led to the recent rescue.

During the first Trump administration, migrants could simply walk north across the border at certain locations in Canada and give themselves up. After being arrested and processed, they were typically released and given access to the country’s generous social safety net. Each month, thousands of immigrants took advantage.

But the loophole allowing that practice was closed in 2023, and illegal northern crossings slowed to a trickle. Current law, however, has its own quirk: It allows refugees who are not apprehended within 14 days of crossing the border into Canada to apply for asylum, giving an incentive to those coming over illegally to do so surreptitiously.

And that has officials worried. Crossing the vast northern border, especially in winter, can be very dangerous. And as the US and Canada tighten security along their mutual boundaries, some fear migrants are crossing in more remote locations and enlisting the help of smuggling networks and organized crime.

“What we’re going to see is much more dangerous and cruel and dehumanizing conditions,” said Ketty Nivyabandi, secretary general of Amnesty International Canada. “If you are fleeing for your life — if you have no other option — people will find a way.”

So far, the surge Canadian officials have been anticipating has yet to materialize.

In December and January, the number of asylum-seekers the Mounted Police intercepted near the Quebec border increased from dozens to around 75 a month, according to the Canadian government. That’s on track with regular, seasonal fluctuations — and is well below the 4,000 or so who were crossing illegally each month until the law was changed in 2023.

“We have not seen a notable change in overall asylum volumes so far this year,” said Remi Lariviere, a spokesperson for the Canadian immigration ministry.

But Canadians are waiting for the other shoe to drop. The day after Trump’s 2024 election, Quebec Premier François Legault warned of a “massive influx of immigrants.”

The Canada-US Border Rights Clinic, which provides legal advice to those considering migrating north, has seen a dramatic increase in inquiries from U.S. residents, according to clinic director Jenn McIntyre. Many of them are refugees from Venezuela, Haiti, Nicaragua and Cuba whose temporary legal status in the U.S. has been terminated by Trump.

“They no longer trust that they might be able to find asylum there,” McIntyre said. “These folks are seeking out another option to keep themselves safe.”

‘As if it were a summer day’

Mark Fewster got the call around 4:30 a.m. on March 7. As fire chief in Mooers, New York — a town of 3,400 people on the Canadian border — he’s used to requests for help when migrants need to be rescued. This was the third call he’d received in a month.

“They’re cold. They’re scared. None of them have ever been prepared for this type of weather,” he said. “Sometimes they just get lost in the woods and they give up.”

Fewster and three other firefighters drove north through a border crossing, picked up Canadian counterparts and arrived at a staging area in Havelock, Quebec. There, they used the Mooers department’s utility terrain vehicle to transport the migrant family through the woods to waiting ambulances.

“They were dressed as if it were a summer day: blue jeans and a pair of tennis shoes,” he said.

Little is known about the family of migrants. Pillarova, the Canadian police spokesperson, declined to identify their country of origin or their current legal status, though she said all four survived the encounter in stable condition.

Their circumstances are hardly unique. Over the past two months, Pillarova said, her agency has conducted rescues along the Quebec border every week. Sometimes stranded migrants call for help, she said, and other times Canadian or U.S. law enforcement officers detect the crossings.

Since Trump’s election, Canada has made a public show of beefing up border enforcement — investing nearly $1 billion in drones, helicopters, mobile surveillance towers and K-9 units — in a failed bid to ward off tariffs on exports to the US.

It’s not clear whether those measures have increased law enforcement encounters with migrants. In a Feb. 25 incident about 20 miles west of Havelock, the Mounted Police rescued five people suffering from hypothermia — and arrested a smuggler and a driver, according to the agency. One of the newly leased helicopters was used in the mission.

In an interview with the Globe last month, Canadian Public Safety Minister David McGuinty said his government was focusing particularly on the region known on the US side of the border as the Swanton Sector, which stretches 295 miles from upstate New York through Vermont and New Hampshire.

“We recognize that this is an area where there have been some attempts, and it’s sometimes tragic — folks who are perishing sometimes in water or on land. Freezing temperatures,” McGuinty said. “We’re focusing on it and investing heavily.”

‘A cat-and-mouse game’

During the last Trump administration, the epicenter of northerly migration was about 12 miles east of Havelock, at an unofficial border crossing known as Roxham Road, which connects Champlain, New York, and Saint-Bernard-de-Lacolle, Quebec.

The two nations had long abided by a treaty known as the Safe Third Country Agreement, which required refugees to make asylum claims in the country in which they first arrived. If a refugee reached the US first and then fled to Canada, they would be returned to the US— and vice versa.

But the agreement had a gaping loophole. If a northbound asylum-seeker was apprehended somewhere other than an official border crossing, they would be arrested and then released while their cases were pending, allowing them to establish new lives in Canada.

As Trump, during his first term, threatened to tighten immigration policies in the US, Canadian Prime Minister Justin Trudeau welcomed those fleeing political persecution and war in their home countries. As a result, many migrants took buses and taxis to the US end of Roxham Road and walked across the border to waiting Mounted Police officers. Between 2017 and 2023, roughly 100,000 migrants made the crossing at Roxham Road.

In March of 2023, under increasing pressure from Canadians fed up with illegal immigration, the countries changed the law to require that even those who crossed at locations such as Roxham Road be returned to the U.S. The number of northbound crossings plummeted.

But even as the two nations closed one loophole, they opened the one allowing those who avoid detection for 14 days to apply for refugee status.

“The situation changed completely,” Pillarova said. “Instead of coming through Roxham Road, they’re coming through anywhere on the border.

“Now they don’t want to be found, so they are hiding. It’s more of a cat-and-mouse game.”

‘A cemetery of people who are fleeing’

Border patrol officers on both sides of the boundary are accustomed to encountering people unprepared for the weather.

“There’s a misconception that it’s safer to cross along the northern border,” said Ryan Brissette, a spokesperson for US Customs and Border Protection. “It’s not any safer. It’s just different.”

Since October, Brissette said, U.S. Border Patrol agents have conducted 26 rescues in the Swanton Sector.

Precisely how many people have died along the northern border is unclear because neither government tracks such deaths, according to Simon Granovsky-Larsen, a professor of politics and international studies at the University of Regina in Saskatchewan. He calls these deaths “essentially invisible.”

Granovsky-Larsen helped orchestrate a study using media reports to establish a partial accounting. The researchers found that between 2020 and 2023, at least 15 people had died along the border. Another 23 perished between 1989 and 2020.

About three-quarters of the total died while traveling south, according to the study. Twenty-three drowned, six died from hypothermia and three were killed in encounters with border patrol agents.

Granovsky-Larsen said he worries that fear itself may exacerbate the situation in the coming months and years.

“There’s a little bit of panic on both sides of the border right now around increased flow of migrants,” he said. That tends to lead governments to further tighten security, he said, prompting yet more dangerous crossings.

The risk, according to Nivyabandi, is a greater loss of life.

“Is that what we want the border to become? A cemetery of people who are fleeing to find decent conditions of life?” she said. “What is the price going to be for these people who are already in the United States and cannot go back?”