Label-shaped device adapted to be applied onto an object for monitoring the time trend of the temperature of the object, said device comprising: a support substrate and a layer of active material applied onto the support, said device being characterized in that: said active material comprises solid solutions of oxyorthosilicates and/or barium halide salts, doped with rare earths and/or metals selected in the group of Na, K and/or Cs; said oxyorthosilicates comprising Lu 2-x Y x SiO 5, where x is a number comprised between 0 and 2, and said barium halide salts comprising BaFX x-1 X' x, where X and X' refer to one of elements selected from Cl, Br and I, and x is comprised between 0 and 1; said active material being adapted to provide: - a first indicator, as immediate visual information associated with the progressive change in colour related to the threshold temperature, based on the progressive variation in the reflectivity of said material as a function of time and temperature, and - a second indicator, based on an optically stimulated luminescence response related to the temperature/time condition to which the object has been subjected in a given period of time, starting from an initially absorbed dose of electromagnetic radiation having an energy exceeding a minimum value dependent on the difference between energetic levels of the molecular structure of said material. a support substrate and a layer of active material applied onto the support, said device being characterized in that: said active material comprises solid solutions of oxyorthosilicates and/or barium halide salts, doped with rare earths and/or metals selected in the group of Na, K and/or Cs; said oxyorthosilicates comprising Lu 2-x Y x SiO 5, where x is a number comprised between 0 and 2, and said barium halide salts comprising BaFX x-1 X' x, where X and X' refer to one of elements selected from Cl, Br and I, and x is comprised between 0 and 1; said active material being adapted to provide: - a first indicator, as immediate visual information associated with the progressive change in colour related to the threshold temperature, based on the progressive variation in the reflectivity of said material as a function of time and temperature, and - a second indicator, based on an optically stimulated luminescence response related to the temperature/time condition to which the object has been subjected in a given period of time, starting from an initially absorbed dose of electromagnetic radiation having an energy exceeding a minimum value dependent on the difference between energetic levels of the molecular structure of said material. - a first indicator, as immediate visual information associated with the progressive change in colour related to the threshold temperature, based on the progressive variation in the reflectivity of said material as a function of time and temperature, and - a second indicator, based on an optically stimulated luminescence response related to the temperature/time condition to which the object has been subjected in a given period of time, starting from an initially absorbed dose of electromagnetic radiation having an energy exceeding a minimum value dependent on the difference between energetic levels of the molecular structure of said material.