A system for aiding an operator in an emergency situation involving a patient, comprising: - at least one portable electronic appliance positionable at the patient and comprising one or more sensors configured to detect one or more biometric parameters of the patient; - at least one mobile device connectable wirelessly to the at least one portable electronic appliance and configured to receive the biometric parameters detected by the at least one portable electronic appliance, the at least one mobile device comprising access to a memory for storing the biometric parameters detected and comprising a display and a processor programmed to receive and process the biometric parameters received, wherein the memory further contains at least one diagnostic algorithm to derive a level of severity of the patient's condition, and wherein the processor is configured to execute the at least one diagnostic algorithm as a function of the biometric parameters received, and to associate the severity level with a corresponding colour appearing on the display of the mobile device; - a data bank accessible by the at least one mobile device and containing a plurality of identification codes, each uniquely assigned to an operator, wherein: - the at least one portable electronic appliance comprises a memory and a processor, wherein the memory contains a program code representing a triage algorithm, run by the processor of said at least one portable electronic appliance and configured to derive the level of severity of the patient as a function of a plurality of parameters, at least some of which are the biometric parameters detected by the at least one portable electronic appliance; - the data bank contains a plurality of professional profile categories for the operator, wherein each identification code of each operator is associated with one of the professional profile categories; - the at least one mobile device comprises a data exchange interface configured to receive the operator's identification code, wherein the memory contains a plurality of predetermined therapeutic procedures, and wherein the processor of the mobile device is programmed to access the data bank and select the professional profile category corresponding to the identification code received, and to select at least one therapeutic procedure from the plurality as a function of the selected professional profile category and as a function of the level of severity of the patient's condition derived by the mobile device, so as to provide the operator with practical indications as to the course of action to be followed, wherein the at least one portable electronic appliance further comprises a display or an element visible from a distance which can be coloured with an interchangeable colour under the control of a processor of the portable electronic appliance to highlight a reference code representing the severity of the patient's conditions as derived by the portable electronic appliance. - at least one portable electronic appliance positionable at the patient and comprising one or more sensors configured to detect one or more biometric parameters of the patient; - at least one mobile device connectable wirelessly to the at least one portable electronic appliance and configured to receive the biometric parameters detected by the at least one portable electronic appliance, the at least one mobile device comprising access to a memory for storing the biometric parameters detected and comprising a display and a processor programmed to receive and process the biometric parameters received, wherein the memory further contains at least one diagnostic algorithm to derive a level of severity of the patient's condition, and wherein the processor is configured to execute the at least one diagnostic algorithm as a function of the biometric parameters received, and to associate the severity level with a corresponding colour appearing on the display of the mobile device; - a data bank accessible by the at least one mobile device and containing a plurality of identification codes, each uniquely assigned to an operator, - the at least one portable electronic appliance comprises a memory and a processor, wherein the memory contains a program code representing a triage algorithm, run by the processor of said at least one portable electronic appliance and configured to derive the level of severity of the patient as a function of a plurality of parameters, at least some of which are the biometric parameters detected by the at least one portable electronic appliance; - the data bank contains a plurality of professional profile categories for the operator, wherein each identification code of each operator is associated with one of the professional profile categories; - the at least one mobile device comprises a data exchange interface configured to receive the operator's identification code, wherein the memory contains a plurality of predetermined therapeutic procedures, and wherein the processor of the mobile device is programmed to access the data bank and select the professional profile category corresponding to the identification code received, and to select at least one therapeutic procedure from the plurality as a function of the selected professional profile category and as a function of the level of severity of the patient's condition derived by the mobile device, so as to provide the operator with practical indications as to the course of action to be followed,