The generation of nuclear reactions using laser-generated proton and ion beams has been investigated for several years by a number of different research teams. Interpreting and understanding these experiments remains a challenge, which suggests that there are phenomena, processes, or effects not considered in the interpretive framework that is usually employed. In this paper, we examine the theoretical case for strong drag heating by the incident ion beam, and the generation of electric fields, which affect the propagation of the ion beam and thus the yield from nuclear reactions. We obtain an analytic metric, , for predicting the regime in which the drag heating heats the target so violently that ion–electron drag is suppressed. This compares favourably to ion kinetic hybrid simulations.