During extreme heat events (EHEs) the public often learns about health protective actions through the media. Visual news coverage can act as a powerful tool to help convey complex health protective actions to the public. Despite the importance of images in helping the public understand the risk, there has been no systematic analysis to assess what images have been used by media outlets in Canada during EHEs. This paper helps to fill that gap by analyzing how the Canadian media visually communicated the risks of extreme heat to the public during the unprecedented 2021 Heat Dome. A review of thousands of online news media articles published about the 2021 Heat Dome in Canada was conducted on five subscription news databases. Overall, 845 images were coded to identify denotative, connotative, and ideological content. Only 16% of these published images implied that heat was dangerous, of which only 40% depicted people, and 46% implied human suffering. Our findings demonstrate that the majority of images used in Canadian news coverage on the 2021 Heat Dome are incompatible with, and frequently contradict, evidence-based heat protective actions. Governments, public health agencies, and other stakeholders engaged in distributing heat preparedness messaging (e.g., journalists) should prioritize improving the images of extreme heat in news coverage to align with evidence-based public health messages. With rising global temperatures due to climate change and the associated increases in the frequency and intensity of extreme heat events, prioritizing these actions is critically important to offset the threat posed to public health.