A computer-implemented method for communicating information to medical responders includes registering a plurality of individuals as potential responders for medical problems, receiving at a central service an indication that a person is having a medical problem and receiving information that identifies a current location of the person, and identifying, from among the registered plurality of individuals, one or more registered individuals who are currently in close proximity to the person having a medical problem. The method also includes transmitting, to the one or more registered individuals, information that identifies the location of the person having a medical problem. The one or more individuals comprise lay responders who are not assigned responsibility to provide lifesaving services in an area around the current location of the person.