[eru]

> [...] the original poster was referring to the more common definition of temperature where at 0K nothing moves anymore.

That's a common simplification, but not really the definition. At the minimum, quantum mechanical effects make this complicated.

But you are right in a sense. From Wikipedia:

> The absolute temperature (Kelvin) scale can be understood loosely as a measure of average kinetic energy. Usually, system temperatures are positive. However, in particular isolated systems, the temperature defined in terms of Boltzmann's entropy can become negative.