What term describes a medium that conveys heat?

The term that accurately describes a medium that conveys heat is "heat-conveying medium." This phrase specifically highlights substances or materials that facilitate the transfer of thermal energy from one place to another. In various contexts, heat-conveying media can include gases, liquids, and solids, all of which have the capacity to transfer heat through conduction, convection, or radiation.

When considering other terms, "convection current" refers specifically to the movement of fluid that carries heat within that fluid, but does not encompass solid mediums or other heat transfer methods. "Thermal conductor" applies mainly to solid materials that efficiently conduct heat, yet it doesn’t encompass all mediums, such as gases or liquids. "Energy transfer method" is broader and includes various ways heat can be transferred, but it does not focus specifically on the mediums that facilitate that transfer. Therefore, the phrase "heat-conveying medium" is the most precise term for describing materials that enable the movement of heat.