Universal or targeted approaches? an experiment about heat risk messaging

Extreme heat causes more deaths than tornadoes and floods combined in the United States. While vulnerable populations are at higher risk of heat-health impacts, anyone can be at risk from extreme heat without appropriate actions. Therefore, heat risk communication efforts, especially those on a wide scale, should engage not only the vulnerable subgroups but also the entire population with the goal of encouraging everyone to take appropriate protective actions during extreme heat events. As one step to achieve this goal, this study examined how to effectively depict people’s susceptibility in heat risk messages. Using a survey experiment (N = 1386), this study compared the effectiveness of four statements that varied how they depicted which types of people were susceptible to heat-health impacts. Relative to traditional messaging that lists specific vulnerable subgroups, a statement that “anyone can be at risk” and a statement without susceptibility information were respectively more effective in making messages personally relevant. Mentioning the “anyone can be at risk” statement and the “certain subgroups are at more risk” statement together reduced belief in the hazard happening compared to mentioning the latter statement individually. Implications for risk communication in broader domains are discussed.