The coupling of edge debonding and thermal buckling of patched beam-plates possessing initial edge detachment is examined for the case when the structure is subjected to a uniform temperature change. The geometrically nonlinear analytical model employed is that established by the authors in a prior work. The problem is recast in a mixed formulation in terms of the transverse deflection and the membrane force to aid in the analysis and physical interpretation. The interaction of edge-debond propagation and thermal buckling is studied. The phenomenon of buckle-trapping, originally observed by the authors in a congruent study, as well as the phenomenon of sling-shot buckling, is seen to manifest itself in the debonding behavior. The evolution of the structure is predicted as a function of given material and geometric parameters from numerical simulations based on analytical solutions of the nonlinear problem. A (propagating) contact zone adjacent to the bonded region is accounted for, and its presence or absence, as well as its nature, is seen to be highly influential in the global as well as local behavior of the structure.