breathing
There are a number of tests which are designed to uncover the content of a person's unconscious mind, but probably the most famous is the Rorschach test (which involves looking at various ink blots and saying what they look like to you).
If they are unconscious and breathing, nothing will happen. If they are unconscious and not breathing, they will die.
To look out for ambush , traffic or other physical dangers, like smell of gasoline , possibility of explosion etc.
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.
Up to (but no longer than) 10 secs
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.