Objective: Maintaining safe physical distance is paramount to slowing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/coronavirus disease 2019 (COVID-19), particularly indoors (e.g., while shopping). We used a health message intervention to motivate grocery store customers to engage in distancing behavior. Method: In an online experiment (N = 206) and a field experiment (N = 268; preregistered on OSF), we used a 2 × 2 between-subjects design and manipulated health messages (a) as gain-framed (“to foster health”) versus loss-framed (“it could be deadly”) and (b) as targeting different beneficiaries (customers themselves versus fellow citizens). In the field experiment, observers rated customers’ distancing behavior during a random confederate encounter and a subsequent interview. We assessed customers’ perceptions of risk and worry, perspective-taking, and state optimism as concurrent psychological processes to investigate customers’ distancing behavior in correlational mediation analyses. Results: Contrary to previous research, the intervention was more effective when pertaining to customers themselves than to their fellow citizens (Experiments 1–2). In addition, loss-framed messages were more effective than gain-framed ones (Experiment 2). The former behavioral effect was accompanied (and statistically mediated) by a concurrent psychological increase in customers’ perceived risk and worry. Conclusions: Owing to their low cost and easy implementation, health messages constitute a promising means to promote physical distancing. Our results show that their effectiveness significantly depends on the framing and target of the health behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved)