The activation energies of two wood sawdusts were determined using an experimental technique based on the crossing-point temperature concept, which was derived from the transient model of self-heating in a solid. The two samples used in this study were treated and untreated sawdust. The activation energies measured were 106 ± 4 kJ mol−1 for the treated sawdust and 90 ± 3 kJ mol−1 for the untreated sawdust. These values are similar to those in previously published results which were obtained using the steady-state model. The transient model provides a quicker yet sufficiently accurate method of determining thermal ignition kinetics.