Todd Korol via Getty Images TORONTO, ON - JANUARY 4: A homeless man tries to keep warm near a steam vent in the bone chilling winter temperatures of -13 in downtown Toronto, Ontario. (Todd Korol/Toronto Star via Getty Images)

In emergency rooms and frontline clinics, patients are triaged based on the urgency of their illness. The sickest are seen first, followed by those in less immediate danger. A high quality health system would connect these efforts to a larger plan to prevent illness and keep people healthy, but still make sure help is there in a hurry when things go wrong.

Unfortunately, in Canada, we aren't there yet.

One of the biggest factors that determines whether people will stay healthy or wind up needing emergency or chronic medical care is where they live. People without access to stable housing are at higher risk of illness, and their likelihood of recovering well from that illness is greatly diminished.

How bad is Canada's housing crisis?

According to the newly released National Shelter Study, Canada's emergency shelters are packed to the rafters. People are languishing in homelessness longer, and their ranks increasingly include seniors, veterans and families with children. Shamefully, Indigenous Canadians are over 10 times more likely than non-Indigenous people to end up in emergency shelter.

This report paints only a partial picture of homelessness in Canada, including only emergency shelters.

Homelessness causes premature death, poor health and is a significant burden on our health-care system.

The sad reality is that over 35,000 Canadians are homeless on a given night with more than 235,000 Canadians experiencing homelessness at some point every year, whether they sleep in shelters, on the street, couch surf, wait unnecessarily in hospital or other temporary accommodation.

Beyond a crisis of housing and poverty, homelessness is a public health emergency. The longer people are homeless, the worse their health becomes. A recent report from British Columbia suggests life expectancy for people experiencing homelessness in that province is half that of other British Columbians.

Some physicians have gone so far as to label homelessness a palliative diagnosis. Not having a home can be lethal. Homelessness causes premature death, poor health and is a significant burden on our health-care system.

Today over 1.5 million Canadian households live in core housing need, with over half of those households living in extreme core housing need (living in poverty and spending over 50 per cent of their income on housing).

The crisis stands to get worse before it gets better as federal operating agreements for older social housing expire and over 300,000 more households risk losing the subsidies that keep their housing affordable.

In the last 20 years, as Canada's population has grown, federal funding for affordable housing has dropped more than 46 per cent. This has meant at least 100,000 units of affordable housing were not built.

Canada's homelessness crisis is the direct result of this federal withdrawal from housing investment.

To make the difficult choices ahead, the government should take a page from medicine and triage.

The new federal government has promised a National Housing Strategy, and has begun consultations. According to the federal minister responsible for this new strategy, Jean-Yves Duclos, "the Government of Canada believes that all Canadians deserve access to housing that meets their needs and that they can afford."

Solving all of Canada's housing problems at once, from homelessness to the rising cost of home ownership, would be wonderful. It is absolutely the right objective, but the sheer scale of the challenge when set against political and fiscal realities will force the government to make some difficult choices -- something Canada Mortgage and Housing Corporation President and CEO, Evan Siddall acknowledged in media interviews recently.

All Canadians deserve safe, decent and affordable housing, but for some, the lack of housing is a matter of life and death. To make the difficult choices ahead, the government should take a page from medicine and triage.

The most pressing problem -- finding stable housing for those who are currently homeless or at risk for homelessness -- is one that, fortunately, can be solved. We need to start by collecting real-time, person specific data on homelessness and expanding the application of the Housing First model of supportive housing for individuals with greater challenges. Housing First is an evidence-based approach to ending homelessness that provides direct access to permanent housing and support. Add to this, better coordination in local planning, targeted investment in affordable rental housing and a national housing benefit, and homelessness in Canada could become rare, brief and non-recurring.

Not only would this take care of those most in need, it would also make available more funds to address elements of our housing challenges that lie further upstream. The cost savings from shelters and emergency rooms could later be applied to the next steps of providing more affordable social housing, preventing more people from falling into homelessness.

In building a National Housing Strategy we can build a future where all Canadians have access to safe, decent and affordable housing. The first step to reaching that goal is urgent action to house Canadians experiencing or at risk for homelessness.