Temperature is the physical quantity that quantitatively describes the idea of "how hot" a body is. From a physical perspective, it is a macroscopic, averaged measure of the kinetic energy of all particles comprising a body, usually molecules and/or atoms. Scientifically, the temperature scale used to quantify temperature is given by thermodynamic's absolute temperature, which is independent of substance. Notably, it also shows the presence of a lower bound for temperature, called the absolute zero, which cannot be reached (but may be approached).