Computational simulations of microstructure evolution provide an efficient tool for the analysis, design, and optimization of materials. Quantitative predictions of microstructure evolution require numerical models that consistently capture all the relevant physical effects. In this context, the multiphase-field method (MPFM) has become a well-established approach for simulating microstructures consisting of multiple phases and moving interfaces [1]. Owing to its computational efficiency, the MPFM is widely employed in a variety of applications, including grain growth and solidification [2]. In simulations of phase transformation processes involving plastification, such as martensitic phase transformations, thermomechanical coupling effects are frequently neglected in the underlying models. However, in the presence of non-zero thermal expansion coefficients, the consideration of coupling terms can influence temperature evolution and the prediction of resulting microstructures, even for small strains and low strain rates [3]. The release of latent heat is a key mechanism in numerous phase transformations, and its consideration is essential to ensure the accurate prediction of microstructure evolution. In particular, the consistent incorporation of latent heat within a thermomechanically coupled phase-field model is a central modeling aspect. This contribution investigates the role of latent heat in the context of displacive phase transformations using a thermomechanically coupled phase-field framework [4]. An elastoplastic inclusion embedded in an elastoplastic matrix is analyzed under various loading conditions, highlighting the impact of latent heat modeling on heat conduction and microstructure evolution. Furthermore, the influence of different driving forces on phase-field evolution is systematically investigated. [1] B. Nestler and H. Garcke and B. Stinner. Physical Review E, Vol. 71, No. 4, pp. 041609 1–6, 2005 [2] L. Q. Chen, Annu. Rev. Mater. Res., Vol 32, No. 1, pp. 113–140, 2002 [3] A. Prahs, M. Reder, D. Schneider, B. Nestler, Int. J. Mech. Sci., Vol 257, 108484, 2023 [4] A. Prahs, D. Schneider, B. Nestler, Continuum Mech. Thermodyn., Vol 37, No. 55, 2025