The worst thing to happen during a thunderstorm is that you or someone in your party is struck by lightning.
Follow these first aid steps immediately:
Go or call for medical help immediately.
Call 911 immediately. This can be difficult if you are in the backcountry and don’t have cell phone service and are a long way from a trailhead or cell service. Tell where you are, provide directions to your location, and tell about the number of strike victims and their condition.
Assess the situation
Check out the situation. Was only one person struck or are there multiple victims? Is the storm still raging? Are you safe when you administer first aid? It’s important not to create more casualties. Be aware of continuing lightning danger to victims and rescuers. Don’t expose yourself, the victims, or rescuers to additional lightning risk. If necessary, move the victim to a safer location before providing first aid. Also consider if the victim was directly struck by lightning or struck by ground currents. Direct strikes are, of course, much more serious.
Check for breathing and heartbeat
Next step is check if the victim is breathing and has a heartbeat. The best places to check for a pulse are at the carotid artery in the neck and the femoral artery behind the knee. Lightning often causes cardiac arrest.
If he is not breathing and does not have a heartbeat, immediately begin providing CPR, following the current Red Cross specs—2 rescue breaths followed by 30 fast chest compressions in 30 seconds. Continue CPR until rescue arrives, although if there is no response after 30 minutes then the chances of survival are slim. It’s a great idea for every climber to take a basic Red Cross first aid course and get CPR certified so that you can do the right thing in emergency situations.
Other Lightning Injuries
Besides cardiac and respiratory arrest, other lightning-caused injuries are burns, shock, brain injury, muscular and skeletal damage, and sometimes blunt trauma including broken bones and ruptured organs. Some victims also experience nervous system disruption with loss of consciousness and amnesia. Treat all these injuries with basic first aid until help arrives. Death by lightning usually results from cardiac arrest.