Question

How do you know something is dead

Answer 1

Answer:

No vital signs

Vital signs include heart rate, respiratory rate, temperature and blood pressure

Answer 2

Is this without equipment?

Depending on what organism you are talking about, animals that can be seen with the unaided eye you can tell that they are dead by studying their bodily movements such as the rise or falling of their chest.

Plants with the unaided eye, the best  indicator is to take a branch or piece off and study the insides color, if it is green then mostly likely they are alive.

Now microscopic organisms are harder to say, it depends on what you are referring to.