The failure mode of a structural component subjected to fire loading is sensitive to its mechanical boundary conditions. It follows that controlling boundary conditions is crucial to obtain a realistic loading scenario with a fire experiment. Hybrid fire testing has been developed for this purpose. Specifically, a structural component under test is loaded using actuators and exposed to fire loading. A coordination algorithm updates actuator setpoints on the fly so that the tested structural component experiences the sought mechanical boundary conditions, e.g., associated with a virtual assembly that is simulated numerically. To enable interoperability of simulation tools and control systems utilized in hybrid testing, a number of middlewares have been proposed, some of which have been adapted to hybrid fire testing. Middlewares facilitate the implementation of hybrid fire testing within the same laboratory. However, the portability of hybrid models from one laboratory to another is critical when different middleware and simulation tools are adopted. A consequence of that is that round-robin verification cannot be easily deployed for hybrid fire testing. In response to this limitation, this paper proposes to craft hybrid fire testing experiments using the Co-Simulation paradigm supported by the Functional Mock-up Interface standard. The methodology is demonstrated experimentally.