Extreme heat is a problem that is expected to become increasingly more common in the future due to the effects of a changing climate. Many cities across Canada have adopted some form of heat alert system that informs citizens not only of the dangers posed by extreme heat, but also what precautions and interventions are available to increase their resilience to this danger. While every human being is potentially at risk from the effects of extreme heat, it does pose a greater threat to some groups more than others. Commonly identified groups that are at a greater risk to extreme heat include the elderly, the homeless, recent immigrants, infants, pregnant women, people with chronic illnesses, and those struggling with addiction and other mental illnesses, among others. All of these groups require different strategies in order to maximize the effects of a heat alert system. In Hamilton, it was observed that many elderly people live in apartments owned and operated by a landlord or in assisted-care facilities. Not only are landlords and caregivers in a prime position to offer aid in the event of a heatwave, but they are also good vectors by which communications regarding extreme heat events, and the appropriate preventative measures, can be transmitted to elderly citizens. Furthermore, they often have a direct or indirect responsibility for acting on these preventative measures that could reduce harm.
With the recognition that the residents most vulnerable to the effects of extreme heat are often also some of the most difficult to establish communications with, the City of Hamilton revised the communication strategy of their heat alerts in order to better serve these at-risk citizens. While extreme heat is hazardous to people from all walks of life, the elderly, people with chronic health conditions, and those struggling with addiction and mental illness are often the most severely threatened. These same groups of people, for various reasons, are often among the most difficult to reach with a broad-spectrum communication strategy. By revising their communication strategy to specifically targeted the landlords and caregivers who are often in close contacts with members of these at-risk groups, the City of Hamilton has improved coverage and penetration of the heat alert system.