There are two more laws that are needed to fully describe thermodynamics.  They are the zeroth law and the third law. 

The name ‘the zeroth law’ comes from the fact that it is a fundamental statement about thermodynamics, but it was not formalized until after the first three laws were stated.  It is such a basic premise, that it was placed before the first three laws—thus zeroth.  It says two basic things:  First, if two different systems are both in equilibrium with the same system, then they are also in equilibrium with each other; and second, two systems in equilibrium with one another will be at the same temperature.

The third law of thermodynamics defines absolute zero, (0 Kelvin) as the lowest possible temperature, and further states that you can’t actually reach it.  Scientists have come very close.  On September 13, 2010, researchers reached a new record low temperature of 100 pK (pico Kelvin) or 0.0000000001 Kelvin.