The Vickers microhardness response of electron-beam physical vapour deposited (EB-PVD) and thermally sprayed duplex thermal barrier coatings has been investigated as a function of temperature. Hardness-temperature plots reveal a transition between a strongly temperature sensitive regime and an athermal regime, and this has been analysed using an activation energy approach. The behavioural transition was found to be similar to 200 degrees C, with hardness falling rapidly above this temperature to similar to 100 kgf mm(-2) at 800 degrees C in each case. Post-annealing hardness-temperature response for the two coatings was very similar despite significant differences in as-received hardness and microstructure. For the temperature-sensitive regime, activation energies for plastic deformation have been calculated as 61 kJ mol(-1) for EB-PVD and 79 kJ mol(-1) for the sprayed coating. Possible deformation mechanisms are discussed, as is the relevance of our data to possible in-service performance.