Thermally stimulated current peaks, corresponding to second-order thermo-luminescence when the recombination lifetime is a rapid function of temperature, are investigated. By numerical calculation, values of the maximum and the half intensity temperatures are calculated. A method for calculating the activation energy by use of the maximum and half intensity temperatures is found empirically in analogy with similar first- and second-order methods. The initial-rise method for calculating the activation energy is also shown to hold true in this case. The value of the parameter μg characterizing the geometrical shape of the peak is found to be around 0·8 for various values of the activation energy and the frequency factor. This, in comparison with the value of about 0·4 for first-order and 0·5 for second-order peaks, indicates very slow decay of this phenomenon at high temperatures.