The viscosity in a non-isothermal differential viscoelastic flow can be temperature-dependent. As described in Introduction, the viscosity will be multiplied by a temperature shift function . For non-isothermal differential viscoelastic flows, the relaxation time is multiplied by the same temperature shift function. Temperature-dependent functions available for non-isothermal differential viscoelastic flows are the Arrhenius law, the Arrhenius approximate law, and the WLF law, all described in Temperature Dependence of Viscosity.