A monitoring device, for remote monitoring of a vital sign of a living subject, the device comprising: remote sensing means for capturing, from a distance, one or more sensor signals that are descriptive of respective characteristics of a body of a living subject; and control means for causing the device to perform at least the following: derive, on basis of said one or more sensor signals, at least a second biometric signal that is descriptive of a second predefined vital sign of said subject for transmission to a server device, detect presence of a first monitoring device that is operating to derive a first biometric signal that is descriptive of a first predefined vital sign of the same subject for transmission to the server device, wherein the first predefined vital sign is the same vital sign as the second predefined vital sign or has a predefined relationship with the second predefined vital sign, and control derivation of said first biometric signal in the detected first monitoring device in response to detecting said first monitoring device, wherein said detecting presence of a first monitoring device comprises: receiving, over a wireless link via the server device, one or more values of the first predefined vital sign carried in said first biometric signal, comparing said one or more values of the first predefined vital sign or a value derived therefrom to temporally corresponding one or more values of the second predefined vital sign carried in said second biometric signal or to a value derived therefrom; and detecting presence of said first monitoring device in response to said comparison indicating similarity between values of the first predefined vital sign and values of the second predefined vital sign or between values derived from the values of the first predefined vital sign and values derived from the values of the second predefined vital sign. remote sensing means for capturing, from a distance, one or more sensor signals that are descriptive of respective characteristics of a body of a living subject; and control means for causing the device to perform at least the following: derive, on basis of said one or more sensor signals, at least a second biometric signal that is descriptive of a second predefined vital sign of said subject for transmission to a server device, detect presence of a first monitoring device that is operating to derive a first biometric signal that is descriptive of a first predefined vital sign of the same subject for transmission to the server device, wherein the first predefined vital sign is the same vital sign as the second predefined vital sign or has a predefined relationship with the second predefined vital sign, and control derivation of said first biometric signal in the detected first monitoring device in response to detecting said first monitoring device, derive, on basis of said one or more sensor signals, at least a second biometric signal that is descriptive of a second predefined vital sign of said subject for transmission to a server device, detect presence of a first monitoring device that is operating to derive a first biometric signal that is descriptive of a first predefined vital sign of the same subject for transmission to the server device, wherein the first predefined vital sign is the same vital sign as the second predefined vital sign or has a predefined relationship with the second predefined vital sign, and control derivation of said first biometric signal in the detected first monitoring device in response to detecting said first monitoring device, wherein said detecting presence of a first monitoring device comprises: receiving, over a wireless link via the server device, one or more values of the first predefined vital sign carried in said first biometric signal, comparing said one or more values of the first predefined vital sign or a value derived therefrom to temporally corresponding one or more values of the second predefined vital sign carried in said second biometric signal or to a value derived therefrom; and detecting presence of said first monitoring device in response to said comparison indicating similarity between values of the first predefined vital sign and values of the second predefined vital sign or between values derived from the values of the first predefined vital sign and values derived from the values of the second predefined vital sign. receiving, over a wireless link via the server device, one or more values of the first predefined vital sign carried in said first biometric signal, comparing said one or more values of the first predefined vital sign or a value derived therefrom to temporally corresponding one or more values of the second predefined vital sign carried in said second biometric signal or to a value derived therefrom; and detecting presence of said first monitoring device in response to said comparison indicating similarity between values of the first predefined vital sign and values of the second predefined vital sign or between values derived from the values of the first predefined vital sign and values derived from the values of the second predefined vital sign.