Heat events can have a major impact on health in Canada and around the world. For example, in 2003 Europe experienced unseasonably hot weather which resulted in approximately 70,000 deaths, and in 2010, nearly 57,000 people died during a Russian heat wave. Canada is not exempt from these risks, just last year extreme heat in BC from June 25–July 1, 2021 killed 619 people. In Ontario, high summer temperatures have been associated with increases in mortality in communities in all regions of the province. Ontario climate change projections indicate a doubling in the number of hot days by mid-century and triple by the end of the century, likely increasing heat-related illnesses and deaths.
The World Health Organization and World Meteorological Organization have stated that the systematic development of early warning systems is essential in reducing heat-related health risks. Until 2016, Ontario’s 36 public health units used a range of warning systems with varying methodologies to determine thresholds for calling alerts. This resulted in a confusing patchwork of alert thresholds and communication protocols. This ended when Clean Air Partnership concluded a four-year facilitated process where all three orders of government worked together to develop a province-wide Heat Warning and Information System (HWIS). All 36 Ontario Public Health Units implemented the system and have been using it ever since. All parties provided countless hours of staff time – a rare and excellent example of cooperation across all orders of government with the goal of health protection.
While the HWIS created is integral to a broader heat alert and response system, all HWIS provides is the alert. The ‘response’ directs the community response to help vulnerable populations and provides individuals with information and other resources to help them take protective actions before and during an extreme heat event. In June 2022, The BC Coroners Office released a review of heat related deaths in BC during the Summer of 2021. In this Report, nearly all key findings related to issues around response, rather than alert. Some of the key findings included:
- A significant lag between the heat alert and the response delivery
- People with chronic health conditions were considerably more likely to die
- Over 67% of those who died were over the age of 70
- Over 56% of those who died lived alone
- Most decedents lived in socially or materially deprived neighbourhoods
Clearly, a majority of those who died were our most vulnerable, so many were old people living alone. In accounting for heat related deaths, we often hear the term ‘excess death’. This term is used because few of these deaths are clinically recognized as being from heat, rather they are coded in hospitals as being from stroke or heart attack. Subsequent epidemiological studies look at ‘normal’ rates of death for a given period and can then attribute the ‘excess’ to environmental causes such as heat. But make no mistake about it, these are parents, grand-parents, friends, neighbours and some of our most vulnerable community members.

The BC report rightly recommends government-level interventions including the creation of a coordinated provincial heat alert and response system, identification of the vulnerable before heat events happen, and prevention and longer-term risk mitigation strategies. What the report does not recommend (and could never enforce) are those interventions that we can chose to make as community members. Can we not take it upon ourselves as individuals to check in on elderly or other vulnerable neighbours during extreme heat events? This would of course require a provincially or federally led communications campaign asking community members to look out for each other, and what the signs of heat distress look like – but has the potential to leverage tremendous social capital to protect health.
Heat will be a more persistent killer with climate change. Government has their part to play in responding to that, but we individuals can do our bit also. And in the vast majority of cases, where a neighbour is perfectly fine and in no distress, wouldn’t it be lovely for them to know that they are cared for a truly part of our community regardless?
By Kevin Behan, Operations Director