Loss of consciousness (a swoon) is usually related to oxygen starvation of the brain, which is caused by decreased blood pressure.
In order to help an unconscious person, you need to know a certain list of actions and be able to use this knowledge in time.
First, the unconscious person should be laid without a pillow and lift his legs. This is done to provide the flow of blood to his head.
Second, we must undo the tightening clothes and open the window (if you're in the room).
Hold the cotton wool soaked in ammonia to his nose. If it is not at hand, you can use cologne or vinegar.
You can act on biologically active points to help stimulate the cerebral circulation. One of these points is in the center of the groove between the upper lip and nose. And the second point - in the center of the fold between the lower lip and chin. Clicking on these points should be strong enough and should be continue for 15 seconds.