Extreme heat is a significant health risk for a large proportion of Toronto’s population. Heat-vulnerable groups include children, older adults, people who are socially isolated or have low incomes, including those who are experiencing homelessness. Toronto Public Health estimates that extreme heat contributes to an average of 120 deaths per year in Toronto and that could increase with climate change. This presentation will highlight work that Toronto Public Health is undertaking to help address the risks of extreme heat including climate forecasting, heat vulnerability mapping, population surveillance, hot weather response and community outreach. Policy opportunities and data needs will also be discussed.