Molecular dynamics (MD) simulations have been used to study the number and arrangement of defects produced by displacement cascades as functions of irradiation temperature, Tirr, in α-iron. The continuum treatment of heat conduction was used to adjust the temperature of the MD boundary atoms throughout the cascade process. This new hybrid model has been applied to cascades of either 2 or 5 keV at 100K, 400K, 600K and 900K. The number of Frenkel pairs decreases by about 20–30% as Tir increases from 100K to 900K, due to the increase in the lifetime of the thermal-spike phase. The same effect also brings about an increase in the proportion of selfinterstitial atoms that form clusters.