The homogeneous change in temperature in a reactive atmosphere arising as a con sequence of small-amplitude initial flow disturbances is studied using high-activation energy asymptotics. The disturbances consist of a velocity non-uniformity and a pres sure gradient non-uniformity which vary linearly with respect to a suitably defined Lagrangian mass variable. The time-dependent flow divergence rates subsequently established by these disturbances, which correspond either to a local fluid expansion or compression, are shown to markedly influence the evolution of thermal energy within the fluid. For sufficiently large fluid expansion rates it is demonstrated that no supercritical thermal explosion, in which large temperature changes occur, is pos sible. The rate of removal of thermal energy in the form of kinetic energy is sufficient to overcome the increase in temperature brought about by chemical reaction. Finally, reaction zone solutions are developed in cases where a supercritical explosion exists.