Device for characterizing a fire, comprising: • at least one stereovision system comprising a first and a second image capture unit that are configured to take images of a fire, said first and second image capture units each having an optical axis (A1, A2), said first and second optical axes being separated from each other by a predetermined distance (d) at the first and second image capture units; and • at least one processing unit configured to combine the images taken by the first and second image capture units of the at least one stereovision system in order to determine at least one geometric characteristic of the fire, which at least one geometric characteristic of the fire can be chosen from: the area of the fire front, the fire area, or the fire volume; the processing unit is configured to determine a radiative flux in different zones exposed to a radiative flux emitted by the fire; characterized in that the radiative flux is determined on the basis of a calibrated linear relationship established between a radiative flux of a reference fire as a function of at least one of the geometric characteristics of the fire and of at least one fire category chosen from among a plurality of predetermined fire categories in order to be able to determine zones exposed to a radiative flux emitted by the fire that exceeds a reference threshold; the device for characterizing a fire further comprises a display unit in communication with the processing unit and configured to depict a map showing the geometric characteristics of the fire and the radiative fluxes in different zones exposed to a radiative flux emitted by the fire. • at least one stereovision system comprising a first and a second image capture unit that are configured to take images of a fire, said first and second image capture units each having an optical axis (A1, A2), said first and second optical axes being separated from each other by a predetermined distance (d) at the first and second image capture units; and • at least one processing unit configured to combine the images taken by the first and second image capture units of the at least one stereovision system in order to determine at least one geometric characteristic of the fire, which at least one geometric characteristic of the fire can be chosen from: the area of the fire front, the fire area, or the fire volume; the processing unit is configured to determine a radiative flux in different zones exposed to a radiative flux emitted by the fire; characterized in that the radiative flux is determined on the basis of a calibrated linear relationship established between a radiative flux of a reference fire as a function of at least one of the geometric characteristics of the fire and of at least one fire category chosen from among a plurality of predetermined fire categories in order to be able to determine zones exposed to a radiative flux emitted by the fire that exceeds a reference threshold; the device for characterizing a fire further comprises a display unit in communication with the processing unit and configured to depict a map showing the geometric characteristics of the fire and the radiative fluxes in different zones exposed to a radiative flux emitted by the fire.