Heat-health messaging in Canada: A review and content analysis of public health authority webpages and resources.

Background: With the growing threat posed by extreme heat, heat-health messaging communicated by public health authorities is critical for raising community awareness and action. This study sought to (i) identify what heat-health content is shared online by Canadian public health authorities and (ii) analyse the material to develop an understanding of the content included within the resources. Study design: Qualitative content analysis. Methods: We reviewed public health authority websites in Canada (n = 99) and extracted all available heat-health content. Content analysis of each resource was performed using descriptive codes related to three categories - populations at greater risk, actions to reduce risk and awareness and knowledge. Results: Within the public health authority websites searched, 417 webpages and online resources were identified (range: 1-43). Over half of the material came from regional health authorities (56 %), primarily located in Ontario and British Columbia (60 %). At least one population at greater risk of heat stress (e.g., older adults, children) (range: 0-24) was mentioned in 59 % of the materials, 81 % mentioned at least one action or behaviour to reduce risk (e.g., stay hydrated) (range: 0-40), and 91 % provided material related to raising awareness and knowledge (range: 0-12). Conclusions: Although a wide array of webpages and online resources were identified, the material content and availability varied considerably across authorities and provinces and territories. These results provide important insights into the composition of heat-health webpages and online resources within Canada and can help guide relevant revisions and additions to the existing heat-health materials.