Canadian Environmental Health Atlas

Understanding Our Environment is Key to Promoting Health and Preventing Disease

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Heat in Toronto

Heat in Toronto

To get a better understanding of the impact of heat on health in Toronto, a recent study mapped the location of 911 ambulance dispatch calls for heat-related illness over the summer periods from 2002 to 2005.12

The rate of heat-related calls to all calls for different parts of Toronto makes it clear that the burden of heat-related illness in the city is dispersed and variable (Figure 1).3 The reasons for proportionately higher rates of heat-related calls in the downtown core are unclear, but poorer housing quality, lack of air conditioning, and local urban heat islands may be responsible.

Areas near the waterfront also had high rates of heat-related 911 calls. This might be explained by the popularity of outdoor activities in the area, which temporarily expose a large and transient population to hot weather.

  • 1. Bassil KL, Cole DC, Moineddin R, et al. Temporal and spatial variation of heat-related illness using 911 medical dispatch data. Environ Res. 2009;109(5):600-606.
  • 2. Bassil KL, Cole DC, Moineddin R, et al. Development of a surveillance case definition for heat-related illness using 911 medical dispatch data. Can J Public Health. 2008 Jul-Aug;99(4):339-343.
  • 3. Reprinted from Environmental Research, 109/5, Bassil KL, Cole DC, Moineddin R, Craig AM, Lou W, Schwartz B, Rea E, Temporal and spatial variation of heat-related illness using 911 medical dispatch data, 600-606, Copyright 2009, with permission from Elsevier. http://dx.doi.org/10.1016/j.envres.2009.03.011. http://www.sciencedirect.com/science/journal/00139351/109/5.