A measure, in kelvins (K,) proportional to the thermal energy of a given body at equilibrium. Note 1: A temperature of 0 K is called "absolute zero," and coincides with the minimum molecular activity (i.e., thermal energy) of matter. Note 2: Thermodynamic temperature was formerly called "absolute temperature. " Note 3: In practice, the International Temperature Scale of 1990 (ITS-90) serves as the basis for high-accuracy temperature measurements in science and technology.