Based on asymptotic solutions to the problem of coupled flow and heat transfer in circular Couette flow of materials whose viscosity and thermal conductivity are polynomial functions of temperature, we obtain expressions for the effect of viscous heating on the gapwise distribution of shear rate under isothermal and adiabatic wall conditions. These expressions are shown to exhibit the anticipated asymptotic behavior as the gap-to-diameter ratio approaches unity and are in agreement with numerical results for a reasonable range of the Nahme number. Following that, we derive explicit rheological corrections for circular Couette–Hatschek viscometers; these account for the effect of viscous heating in the presence of temperature-dependent fluid properties and are reliable for values of the correction factor down to around 0.8.