AbstractDuring an emergency, it is necessary to quickly disseminate messages to the public. These communications often provide information about the emergency as well as guidance or advice aimed at ensuring the safety of the population. Successful emergency communication depends upon how rapidly and reliably a message can be disseminated, but also on how people respond to the message that they receive. To assist emergency planners tasked with developing message sets for future incidents, in this paper we report a systematic review of all studies that assessed the impact of mobile telephone alerting systems on intended and actual behaviour, to identify factors that affect their likely impact. We searched multiple databases and conferred with topic experts, resulting in a total of 22 studies which met the inclusion criteria. Our results indicate that limited data exist on how people respond to text‐based warning messages and that much of the data is poor quality, indicating a need for more real‐world studies.