Communication measures can raise protective behavior regarding climate change, natural hazards, and other health risks. For being effective in such communication, we designed a five-steps methodology and applied it to health-protective behavior during heat extremes in Austria. The five steps are as follows: (1) target group selection, a multicriteria assessment (MCA) to identify the most important target group(s)this led to the identification of mobile health care nurses as our primary target group; (2) target group analysis by interviews to identify drivers of and barriers to protective behaviorfor the mobile health care nurses, the drivers were their climate change perceptions, control beliefs, perceptions of role models, and extent of thinking about heat and health, and the barriers were fatalism and work stress; (3) development of target group specific communication formats addressing the identified drivers and barriersfor the nurses, we designed a workshop format, animated videos, and two print formats; (4) pretest of formats in focus groupsthese revealed our formats were effective in increasing heat risk awareness, competence, and protective behavior among the nurses; (5) improvement of formats based on pretest resultsfor example, we modified the workshop format to become a venue for mutual learning. These five steps can be applied to other projects where awareness, competence, or behavior shall be increased by means of communication.