A clothing item or wearable accessory for use with a system for calculating the exposure to sun radiation received on the different parts of the body by a person, including a wearable device (1) that communicates with a telecommunication mobile device (2) and a remote computing unit (3) operatively connected to satellites (4) to receive georeferenced data related to solar irradiation over time and set to associate the solar irradiance data to the geographical position, the posture and the orientation of the person (P) or of parts of the person's body.
