  For astrophysical reacting flows, operator splitting is commonly used to
couple hydrodynamics and reactions. Each process operates independent of one
another, but by staggering the updates in a symmetric fashion (via Strang
splitting) second order accuracy in time can be achieved. However,
approximations are often made to the reacting system, including the choice of
whether or not to integrate temperature with the species. Here we demonstrate
through a simple convergence test that integrating an energy equation together
with reactions achieves the best convergence when modeling reactive flows with
Strang splitting. Additionally, second order convergence cannot be achieved
without integrating an energy or temperature equation.
