This entry contributed by Marie-Jessique Gonzalez
If an object with a higher temperature comes in contact with a lower temperature object, it will transfer heat to the lower temperature object. The objects will approach the same temperature, and in the absence of loss to other objects, they will maintain a single constant temperature. Therefore, thermal equilibrium is attained. Thermal equilibrium is the subject of the zeroth law of thermodynamics.
Local Thermodynamic Equilibrium, Plate Thermal Equilibrium, Sphere Thermal Equilibrium, Zeroth Law of Thermodynamics