Due to climate change, heat events in Canada have become more extreme in intensity and frequency and will continue to do so according to the Intergovernmental Panel on Climate Change's global predictions. Environmental justice research has indicated that extreme heat exposure disproportionally affects socio-economically disadvantaged populations in cities. The objective of this research was to determine whether such a phenomenon exists in Montreal, Canada. Temperature data were obtained through in-situ sensors and governmental weather stations, while census data were retrieved from Statistics Canada through the Census mapper. Correlation tests were run between temperature and five demographic and socio-economic variables measured inside a 500 m buffer around the temperature sensors. The variables included Indigenous Peoples (IND), people of 65 years old and over (Over 65), people between 25 and 64 years old without a high school degree (No HS), and low-income (LI). A positive correlation was found for LI and No HS (p < 0.05). A regression test performed with interpolated temperature and the demographic and socio-economic variables across the study area revealed no significant correlation due to spatial heterogeneity.