Abstract: The invention relates to a portable device which is designed to be carried on the body of a child, said child being a baby or a small child. The device includes one or more sensors for detecting multiple vital parameters of the child, wherein the vital parameters at least include the heart rate, oxygen saturation, and respiratory rate; analysis software which is configured so as to predict at least one current or future physiological state of the child as a function of the heart rate, oxygen saturation, and respiratory rate measured by the sensors; and an interface for transmitting the prediction result relating to the at least one physiological state to a mobile telecommunication device of a user and/or to a server computer system.