Extreme heat events are a growing threat to the health of Canadians as the climate continues to change. Windsor is the southernmost city in Canada and experiences some of the warmest summertime temperatures in the country. During summer months, temperatures are often above 30°C and average humidex values are the highest in Canada. Climate change is expected to significantly increase the number of extreme heat days annually in the region. This may exacerbate the risk of heat-related illness and deaths, particularly among seniors, people with chronic illnesses and other vulnerable groups. Extreme heat can cause serious illness and even death if people do not take protective measures in hot conditions. It can lead to skin rashes, cramps, dehydration, syncope (fainting), exhaustion and heat stroke. In Windsor, there is a strong association between excess mortality and temperature; at approximately 29°C, excess mortality begins to increase as ambient temperatures increase.
Development of an Urban Heat Island Effect (UHIE) map was initiated in order to generate a decision-making tool that could be used to visualize the impacts of the UHIE, to develop a mitigation strategy, and to inform heat alert and response planning in Windsor. The map was designed to represent the temperature differences throughout the city resulting from the UHIE, point data depicting the location facilities and businesses that are integral to heat alert and response, and socio-economic census data to account for the variance in heat vulnerability between different populations. The data selected for inclusion in the mapping was based on the detailed report Assessment of Vulnerability to the Health Impacts of Extreme Heat in the City of Windsor completed by Health Canada.