The total entropy of a system either increases or remains constant in any process; it never decreases. For example, heat transfer cannot occur spontaneously from cold to hot, because entropy would decrease.

Will entropy end the world?

The 'heat-death' of the universe is when the universe has reached a state of maximum entropy. This happens when all available energy (such as from a hot source) has moved to places of less energy (such as a colder source). ... Eventually, the universe will be too cold to support any life, it will end in a whimper.

What happens when entropy reaches maximum?

As entropy in the universe continues to increase, heat will continue to spread until the system has reached maximum equilibrium, meaning that everything will degrade into sole particles and a swirl of radiation.