A phase slip is an elementary dissipative quantum event in which the superconducting phase difference across a normal metal weak link advances by 2π, releasing energy into the electronic system. In this talk, I present a theoretical model for the coupled phase and thermal dynamics of a Superconductor-Normal metal-Superconductor (SNS) loop during a single phase slip event, motivated by the recent calorimetric experiment by Gümüş et al. (Nature Physics, 2023) which first resolved the thermal signature of such an event. Starting from the energy landscape of the SNS loop and macroscopic conservation laws, I derive and simulate the real-time evolution of the electronic temperature during the phase slip, and discuss the comparison between our theoretical predictions and the experimental data.