> Temperature is monotonically related to energy content. A warmer system has more energy than a colder one, all else being equal. In equilibrium, the temperat

> Temperature is monotonically related to energy content. A warmer system has more energy than a colder one, all else being equal. In equilibrium, the temperature of the water is directly related to the energy content, with the heat capacity being the conversion factor. But under the thermodynamic definition, the temperature of the system depends not only on its energy but also on its entropy. And one of the points the article is making is that even when we know the total amount of energy entering or leaving the system, its entropy may not be nearly so easy to measure or calculate when its state is far from equilibrium.