Trust‐Building Communication for Extreme Heat Preparedness

Extreme heat events pose significant challenges for risk management and communication, particularly as many climate governance leaders are viewed as untrustworthy sources. While research shows that trusted sources are more persuasive, strategies for building trust remain unclear. This study employed a randomized, controlled factorial experiment with 12 message conditions (three message trust conditions × three agency levels plus controls) and a politically representative US sample (N = 551) recruited via Prolific Academic. Participants viewed 90 s video messages designed to manipulate trust in emergency management agencies while persuading Americans to take protective actions in response to extreme heat risks. Participants completed validated scales measuring perceived source trustworthiness, attitudes toward extreme heat risk, attribution of heat events to climate change, and behavioral intentions. Results indicate that experimental trust-building messaging and specified government agency levels significantly influenced perceived trustworthiness, with local emergency management agencies rated more trustworthy than state or national agencies. Messages designed to convey trustworthiness significantly improved attitudes toward heat risk perception. These findings suggest that trust-building strategies and local framing can enhance persuasive efficacy in extreme heat preparedness communication. Implications for theory and best practices in emergency risk messaging are discussed.