An imbalance in pressure changes the volume of a system, resulting in work energy entering or exiting the system. An imbalance of temperature results in heat energy entering or exiting a system, but ...An imbalance in pressure changes the volume of a system, resulting in work energy entering or exiting the system. An imbalance of temperature results in heat energy entering or exiting a system, but what is the state variable (analogous to volume) that this imbalance changes?