The heat death of the universe will happen when the universe reaches a maximum state of entropy trillions and trillions of years from now.
Humanity will be long gone before that. Eventually the universe will fade into essentially nothingness. Humanity will only be around for a fraction of a second in the life of the universe. So essentially we are all some independent part of the same stream of consciousness. All thinking alike in the single blip in the life of the universe that could perceive and fortell what is happening. To exist is only for a moment then it becomes an irrelevant term. Eventually we will all fade into the darkness to be one with one another in the unholy matrimony of non-existence. So for today there is no difference in "us" and "we" simply "is", as I invite myself to become part of "one".