Public health action on extreme heat in three Canadian provinces: a scoping review.

Objectives: To examine how public health activities addressing extreme heat align with Canada's Essential Public Health Functions; the roles taken by public health authorities in collaborative responses; and the extent of heat response evaluations to date in three Canadian provinces. Methods: Following Arksey and O'Malley's Framework, we conducted a scoping review of academic and grey literature on public health heat strategies in British Columbia, Ontario, and Quebec, Canada between 2005 and 2026. We searched ten academic databases, and scanned government and non-government websites. Academic sources were double-screened using Covidence software. Results: We identified 26 peer-reviewed articles (British Columbia: 7, Ontario: 8, and Quebec: 16) and 429 grey literature sources. Nine sources evaluated heat responses across the three provinces. Public health authorities across the provinces fulfilled similar Essential Public Health Functions, focused on downstream response including establishing heat alert systems and communicating preventative health information. Public health actors primarily play advisory roles in intersectoral heat responses, though some co-lead responses. Conclusion: Our findings suggest ongoing gaps in upstream public health heat strategies, and meaningful collaborations with at-risk communities.