If they are unconscious and breathing, nothing will happen. If they are unconscious and not breathing, they will die.
When a diabetic person becomes unconscious, check for their emergency glucagon injection kit, as you are calling 911. Once the person is conscious, treat the same as you would a person who has not been unconscious.
When the person does not respond
Go to sleep.
The powder that can make a person unconscious is called "बेहोश करने वाली पाउडर" in Hindi.
Depends on the person and situation.
a person needs oxygen and glucose for respiration
Too much carbon dioxide will kill any animal or human. We need oxygen to live. As the levels rise, the need for air increases and a person will begin to breathe harder and deeper. If the levels get even higher, they will try to get out of the room or become unconscious.
chloroform
tap on their shoulders and repeatedly ask if they are OK. if no response they are most likely unconscious.
breathing
These substances are called narcotics.