One or more processors determine whether a hazard that is detected by a first mobile device exists based on data received from at least one second mobile device. The second mobile device is within a proximity to the first mobile device, which is determined based on a type of the hazard. One or more processors respond to a determination that the hazard does exist by determining a course of action. The course of action is configured for a user based on at least one attribute of the user. One or more processors send the course of action to the first mobile device.