Communicating about new or unknown health risks is challenging because it requires audiences to engage with and process novel and often complex health information. This study examines how texts can convey awareness and increase knowledge about health risks people are unaware of. The focus is on how text genre (narrative, expository, and mixed-genre) affects relevant emotional (arousal, transportation) and cognitive outcomes (knowledge and risk severity), measured using both online (electrodermal activity) and offline self-report measures. Mixed-effects model analyses revealed that narrative texts exhibit the highest self-reported arousal, transportation, and risk severity. Additionally, transportation mediates the relationship between text genre and risk severity. Ultimately, mixed-genre texts produced significantly higher arousal peaks and confidence ratings on knowledge posttests compared to expository texts. Taken together, the findings suggest that narrative texts perform better at raising awareness, whereas mixed-genre texts seem more effective in learning. The implications for health risk communication are discussed.