Which is colder-minus 1 degree or minus 5 degrees?

Five degrees below zero is colder than one degree below zero. The larger the number in a negative number, the smaller the value it represents.

There is no concept of the highest temperature in classical thermodynamics, only the theoretical lowest temperature "absolute zero". The third law of thermodynamics points out that "absolute zero" cannot be achieved through limited steps.

In statistical thermodynamics, temperature has been given a new physical concept-a thermodynamic quantity that describes the intensity property of internal energy in the system by the rate of change of system chaos (namely entropy). Thus, a new theoretical field of "thermodynamic negative temperature region" was created.