The value of the scaling parameter Eeff of the temperature dependence for current generated in silicon bulk is investigated for highly irradiated devices. Measurements of devices irradiated to fluences above 1×1015neqcm-2 have shown a different temperature scaling behaviour than devices irradiated to lower fluences. This paper presents the determination of the parameter Eeff for diodes irradiated with protons up to fluences of 3×1015 neqcm-2 in the bias range from 0 V to 1000 V at temperatures from −36° to 0° at different stages of annealing. It is shown that Eeff for highly irradiated devices depends on the applied electric field: below depletion voltage, Eeff is observed to have a lower value than above depletion voltage.