Go to sleep.
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.
No, it is not possible to be conscious of being unconscious. When a person is unconscious, they are not aware of their state of mind or surroundings.
When the person does not respond
The powder that can make a person unconscious is called "बेहोश करने वाली पाउडर" in Hindi.
Depends on the person and situation.
chloroform
a unconscious person needs oxygen because without oxygen they will sufer serious brain damage and can possable die.
tap on their shoulders and repeatedly ask if they are OK. if no response they are most likely unconscious.
These substances are called narcotics.
taste
breathing