The invention relates to a method for establishing an association (100) between a user (10) and at least a recipient (20), comprising the following steps: instancing a geographical area; automatically monitoring the entrance within said geographical area of a user (10) and establishing an association (100) between a mobile computer device (12) of the user (10) and a mobile computer device (22) of the recipient (20); and upon detection of a critical condition by a sensor (14) of a condition of the user, automatically alerting the recipient (20) accordingly, through the established association (100). The invention also relates to a system for performing such a method. (Figure 1)