it depends if they have just fainted or if they are going to be out for a while, it also depends on the situation. If the person faints you should rub their hands and arms and try to get circulation running. also they should be on a relatively flat surface and after they wake up, give them some food. Nothing too heavy, maybe something like crackers, and also something to drink. Something that has suger in it so that their glucose levels will stabilize.
If they are unconscious and breathing, nothing will happen. If they are unconscious and not breathing, they will die.
breathing
Could be. Breathing is not a response. A person who is unconscious would be unresponsive and still breathing.
CPR should be performed if a person is unconscious and not breathing
Up to (but no longer than) 10 secs
To check for a response from an unconscious person, start by gently tapping their shoulder and asking loudly, "Are you okay? Can you hear me?" If there is no response, try to assess their breathing and pulse. If they are not breathing or do not have a pulse, begin CPR and call for emergency medical assistance immediately.
First perform an Initial Assessment. Open the airway, Check for breathing, if there is no breathing give two rescue breaths. If the rescue breaths go in and make the chest clearly rise check for a pulse. IF there is no pulse begin CPR.
So you don't stop breathing even when you are asleep or unconscious.
Passed Out But You Are Still Breathing
When a person has stopped breathing and can not breathe on his own, rescue breathing (or Mouth-To-Mouth Resuscitation) is given to try and saved the persons live (in addition to CPR and/or defibrilation).
Yes, if a person is unconscious and breathing, it's important to place them on their side in a recovery position to ensure their airway remains open and clear. This can help prevent choking and facilitate better breathing until medical help arrives.
Make sure that it is necessary. If the person is unconscious and breathing, CPR is not indicated; you may do more harm than good.