  Recently, Shete et al. [Phys. Rev. Fluids 7, 024601 (2022)] explored the
characteristics of passive scalars in the presence of a uniform mean gradient,
mixed by stationary isotropic turbulence. They concluded that at high Reynolds
and Schmidt numbers, the presence of both inertial-convective and
viscous-convective ranges, renders the statistics of the scalar and velocity
fluctuations to behave similarly. However, their data included Schmidt numbers
of 0.1, 0.7, 1.0 and 7.0, only the last of which can (at best) be regarded as
moderately high. Additionally, they do not consider already available data in
the literature at substantially higher Schmidt number of up to 512. By
including these data, we demonstrate here that the differences between velocity
and scalar statistics show no vanishing trends with increasing Reynolds and
Schmidt numbers, and essential differences remain in tact at all Reynolds and
Schmidt numbers.
