Method for determining a spatial distribution R x, y f of a parameter of interest representative of the electrical power production of an electrochemical cell, said cell including two electrodes separated from one another by an electrolyte and placed between two bipolar plates suitable for bringing reactive species to the electrodes and for removing the heat produced by the cell in operation, comprising the following steps: i) providing (110; 210) an electrochemical cell, within which the parameter of interest is distributed with an initial spatial distribution R x, y i and for which the spatial distribution of a temperature within the electrochemical cell in operation has at least one local value higher than or equal to a preset maximum local value; ii) defining (120; 220) a spatial distribution T x, y c of a set-point temperature (T c) within the electrochemical cell in operation, said distribution being such that the local temperature values are lower than preset maximum local values; iii) measuring (130; 230) a spatial distribution D x, y r of a first thermal quantity representative of the local removal of heat (D r) within said electrochemical cell in operation; iv) estimating (140; 240) a spatial distribution Q x, y e of a second thermal quantity (Q e) representative of the local production of heat (Q e) within said electrochemical cell in operation, depending on said spatial distribution T x, y c of the set-point temperature (T c) and on said measured spatial distribution D x, y r of the first thermal quantity (D r), so that the spatial distribution of the temperature of said electrochemical cell in operation, the first thermal quantity (D r) of which cell having said measured spatial distribution D x, y r and the second thermal quantity (Q e) of which cell having said estimated spatial distribution Q x, y e, is substantially equal to that T x, y c of the set-point temperature (T c); and v) determining (150; 250) a spatial distribution R x, y f of the parameter of interest depending on the estimated spatial distribution Q x, y e of the second thermal quantity (Q e), wherein the step of estimating a spatial distribution of the second thermal quantity includes: - a phase of producing a mesh of a cooling circuit of at least one bipolar plate of the electrochemical cell, through which circuit a heat-transfer fluid is intended to flow; and - a phase of simulating numerically by computer the second thermal quantity on said mesh, by solving a discrete numerical model expressing the second thermal quantity as a function of the local temperature and of the first thermal quantity. i) providing (110; 210) an electrochemical cell, within which the parameter of interest is distributed with an initial spatial distribution R x, y i and for which the spatial distribution of a temperature within the electrochemical cell in operation has at least one local value higher than or equal to a preset maximum local value; ii) defining (120; 220) a spatial distribution T x, y c of a set-point temperature (T c) within the electrochemical cell in operation, said distribution being such that the local temperature values are lower than preset maximum local values; iii) measuring (130; 230) a spatial distribution D x, y r of a first thermal quantity representative of the local removal of heat (D r) within said electrochemical cell in operation; iv) estimating (140; 240) a spatial distribution Q x, y e of a second thermal quantity (Q e) representative of the local production of heat (Q e) within said electrochemical cell in operation, depending on said spatial distribution T x, y c of the set-point temperature (T c) and on said measured spatial distribution D x, y r of the first thermal quantity (D r), so that the spatial distribution of the temperature of said electrochemical cell in operation, the first thermal quantity (D r) of which cell having said measured spatial distribution D x, y r and the second thermal quantity (Q e) of which cell having said estimated spatial distribution Q x, y e, is substantially equal to that T x, y c of the set-point temperature (T c); and v) determining (150; 250) a spatial distribution R x, y f of the parameter of interest depending on the estimated spatial distribution Q x, y e of the second thermal quantity (Q e), - a phase of producing a mesh of a cooling circuit of at least one bipolar plate of the electrochemical cell, through which circuit a heat-transfer fluid is intended to flow; and - a phase of simulating numerically by computer the second thermal quantity on said mesh, by solving a discrete numerical model expressing the second thermal quantity as a function of the local temperature and of the first thermal quantity.