Lightning can also kill a person who's merely close to the strike. As the electrical wave spreads out through the wet ground, it can pass through the body of a person who's in contact with the ground. The amount of damage depends on the distance from the strike, how easily the electricity can enter and exit your body, and how far apart the entrance and exit points are. For example, a biker who's actively riding his bike 10 feet from a strike will suffer less injury than a hiker sitting in wet clothes on the ground, because the electricity can't come up through the rubber tires as easily as it can pass through wet clothing. (What's more, any electricity that makes it past the wheels will find it easier to run through the bike frame than through the biker's body.) With a nearby strike, it's better if you're squatting or standing, because the person who's sitting or lying provides an entrance point and exit point that are further apart than someone whose body is touching the ground in only one spot.
After a lightning strike, quickly shake each person who's lying on the ground. If they respond in any way, immediately go on to the next victim. If the person is unresponsive, check for breathing. If the victim is breathing, position him on his side and go on to the next victim.
When you find a victim who's not breathing, give two mouth-to-mouth breaths then check the carotid artery for a pulse. If there's a pulse, assign someone to continue rescue breathing until the victim is breathing on his own. Go on to the next victim.
If a victim has no pulse, assign someone to do chest compressions and another to do rescue breathing and to watch for a return of the pulse. If your available rescuers are limited, one individual can do both chest compressions and respirations.
Send someone for help as quickly as possible. But because lightning-strike victims often resume breathing after a short period of rescue breathing, if your choice is sending a biker immediately versus having him keep a victim alive, have your "messenger" give rescue breathing for 5 minutes. If a victim responds, you then have a man free to go for help. If none does, stop CPR on a pulseless victim to send his rescuer down the trail.
If you are alone with multiple non-breathing lightning-strike victims, you have a problem. If you can resuscitate only one person, it would make sense to provide rescue breathing to a victim who still has a pulse. But by dragging one victim close to another, you could provide adequate rescue breathing to more than one. By alternating five breaths for one victim, five for another, you could possibly keep two or even three victims alive during the few minutes it takes for the respiratory muscles to recover.