Successful warnings are those that are taken seriously and responded to in a timely and effective manner. Multiple factors may have an impact on whether people respond to a warning, including:

• Individual characteristics—Age, education, language, access and functional needs, family composition, and length of residency, among others.
• Perceptions—Previous experience with a hazard and perceptions of proximity and risk.
• Message source—Who issues the warning, credibility of the warning source, and the level of trust in that source.
• The message itself—Accuracy, clarity, timeliness, consistency, and specificity of the message, and focus on immediate needs.