The contribution at hand aims at the formulation of a promising constitutive model for solids exhibiting thermo-viscoelastic characteristics. Temperature dependency and nonlinear creep properties are included into this material formulation. In general, a phenomenological constitutive formulation considering isotropic thermoviscoelasticity at finite strains is introduced based upon a multiplicative split of the deformation gradient. The evolution equations for the inelastic deformation gradient are introduced in a thermo-dynamically consistent manner. In particular, the present approach focuses on an inelastic incompressibility condition and the principle of maximum of dissipation. The derivation starts from a well-defined Helmholtz energy function, which also includes a volumetric thermal deformation. For simplicity, isotropic thermal conductivity behavior is taken into account. The set of constitutive equations is consistently linearized and incorporated into a Newton-type solver. The physical applicability of the present formulation is validated by a promising numerical study, which has also demonstrated favourable numerical stability and robustness.