AlGaN/GaN HEMTs have become the technology of choice for RF power amplification, thus exacerbating the importance of accurate circuital models for them. As known, these devices suffer from significant electron trapping effects, which strongly impact their behavior, making a trapping model critical to correctly predict the HEMT response. Physically, it is well known that electron trapping is thermally activated, and, consequently, the device’s thermal response interacts with the trapping dynamics. In this paper, we propose a simple circuital trapping model that incorporates the thermal dependency, along with the required characterization techniques for its correct extraction, and show the importance of the trapping thermal dependency inclusion in the prediction of device behavior.