The temperature and concentration fields produced by turbulent mixing of two reactants undergoing a one‐step, very rapid, irreversible, exothermic reaction are studied. Temperature and concentration fields decay in two stages: kinetically driven and diffusion controlled. Stochastic solutions are derived for the first stage, the asymptotic state of which displays all the characteristics of species segregration. In particlar, only a weak correlation between the concentration and temperature fields is generated in the first stage. For the special case of equal mass diffusivities and a Lewis number of one the solution to the second stage is obtained in terms of the solution of a nonreacting binary mixing problem. An approximate solution for Lewis numbers different from one is proposed. The temperature field seems to decay with an effective thermal diffusivity determined by the smaller of the molecular mass and thermal diffusivities.