Lightning:

1. Lightning: How Dangerous Is It?

2. Lightning: What is it? • Ask Ben, people didn’t know until then • Temp: air commonly heated to 50,000F degrees, can be 100k F • Can travel up to 115 miles, commonly dangerous to 10 • Can be: • cloud to cloud • Intracloud • Cloud to ground (what we care about) • Positive and negative, positive more powerful • Has equivalent energy to 45 gallons of gas . . . . . . Burned in just a few milliseconds • Average T-storm same energy as an A-bomb • 10 million to 100,000,000 Volts, 30,000 amps ave, 1 Terawatt in largest bolts (An electric arc welder is 2-400 amps)

3. Who’s at Risk • In the US, 50+ people die of lightning each year • An average person’s lifetime chance of being hit is about 1 in 7000 • But: • What do we do for a living? • Where are we working? • When are we outside most with the most people? • How far are we from “safety?” • If you are outside during a storm your chances of being hit are about 1 in 28,000 • 70% of victims happen between June and August between 2 and 6 pm

4. Lightning: What it can do to you • It can kill you • 10-30% mortality rate • Heart stoppage • Respiratory failure • Destroyed organs or bones • It can injure you both short term and permanently! • Up to 80% of directly hit victims have long-term injuries • Can cause: • Burns (although not as often as you’d expect) • Blindness • Deafness • Nerve damage • Drain Bramage

5. More Medical Symptoms • What are the Medical Symptoms? • Injury to the nervous system, often with brain injury and nerve injury. Serious burns seldom occur. People who do not suffer cardiac arrest at the time of the incident may experience lesser symptoms, which often clear over a few days: • Muscle soreness • Headache, nausea, stomach upset and other post-concussion types of symptoms • Mild confusion, memory slowness or mental clouding • Dizziness, balance problems • Longer term problems may include: • Problems coding new information and accessing old information • Problems multitasking • Slower reaction time • Distractibility • Irritability and personality change • Inattentiveness or forgetfulness • Headaches which do not resolve with usual OTC meds • Chronic pain from nerve injury • Ringing in the ears and dizziness or balance problems • Difficulty sleeping, sometimes sleeping excessively at first and later only two or three hours at a time • Delayed Symptoms may include: • Personality changes/self-isolation • Irritability and embarrassment because they can't remember people, job responsibilities and key information • Difficulty carrying on a conversation • Depression • Chronic pain and headaches

6. Lightning: Types of Hits • Direct • You become part of the electrical path • You touch something that is part of the direct path • The voltage jumps from something to (and through) you • Blast—you’re hit by debris, hearing injured by proximity

7. Lightning: Types of Hits • Indirect • Step Potential • By far most common lightning injury • You’re near to the direct strike, generally less than 30 yards • The dissipating electricity goes through your body rather than the earth • The differential voltage drop is the danger • EMP (Electro-Magnetic Pulse) • Pacemakers (that’s a surprise—Not!) • Biological functions like: • Beating heart • Breathing • Consciousness • Muscle control

8. Lightning: Types of Hits • Secondary • Explosions • Part of what was hit, a tree for example • Fire • In a sense the Arizona hotshot crew was killed by this • Accidents • Loss of control of equipment, especially vehicles if tire blow out

10. Lightning: When are you at Risk • Risk: • You’re at risk when: • You can hear thunder (up to 10 miles distant) • You can see lightning (even heat lightning) • There’s a Thunderstorm happening • You’re told there’s a storm in the area (radio, cell) • The storm ended less than 30 minutes ago • To tell how far away a storm is in miles, count the seconds from the flash to the bang and divide by 5 • You’re in significant danger when: • You’re in the main part of a Thunderstorm • Downwelling, High sudden winds • Large raindrops • Hail • Active Lightning • You’re in Extreme danger when: • Your hair stands up • You can “feel” the charge in the air

11. Lightning: What to do • Make sure everyone in your area is aware of the storm and what to do—notify others, begin moving to safety! • Best: • Get indoors (but a shed or other unimproved shelter won’t help) • Get inside a vehicle (but not a convertible, even with the roof up) • If you’re outside: • Get away from conductors • Anything taller that the surroundings • Anything large and metal (and especially tall) • Off of mountain tops and prominent ridges • Try to get to shelter (major building, vehicle) • Get in a thickly wooded area, preferably in a depression

12. Lightning: What to not do • Inside a building, avoid: • Plumbing • Using anything electrical connected with a wire • Consensus is stand-alone battery operated devices are ok • Basements • Just like being outside, you can be affected by step potential • Windows • Charge can go through a window • Windows can break due to wind, hail, or debris • Inside a car, avoid • The rear window area • Touching anything you don’t need to: • Steering wheel, radio, exterior arm rests

13. Lightning: What to do-Outside • If you suspect a strike to you is imminent (hair standing on end, severely “energized” feel to the air • Stay away from metal • Do NOT take shelter under a tree • Squat with your feet as close together as possible • Touch the ground only with your feet • Tuck your head into your knees, cover your ears • Do NOT lie prone • If with other people, spread out so not everyone is affected if there’s a strike

15. If you’re indirectly hit: • You’ll likely: • Have been knocked over • Be partially to completely deaf (ringing ears, headache) • May have been knocked unconscious and have no memory of the strike) • Be disoriented • Be nauseous • Feel “wired” • Should get medical attention • If you’re directly hit, your injuries are likely to be much more severe.

16. After a Strike • Check on others! • Many lightning victims suffer cardiac or respiratory arrest and can be resuscitated. Ironically an AED can get them going again • Lighting strike victims are NOT electrically dangerous! • If there are severely hurt victims, call for emergency help immediately • Remove victim(s) from severe imminent danger if possible (fire, explosion, drowning) • Report the injury or near miss, • Get medical attention as needed

17. Lightning Myths • Lightning doesn’t hit the same place twice • You’re safe in a car because of the rubber tires • A person who’s been struck by lightning is dangerous to touch • Inside a modern building keeps you completely safe • If there are no clouds visible or the storm is very distant you are safe. (“Bolt out of the blue”) • Jewelry, buttons, implants, braces etc. make you a likelier lightning target • It’s ok to finish up what you are doing if a storm is coming • Talking on a radio or cell phone increases your chances of being hit (only if you are connected to a big antenna) • Lie flat on the ground if a strike is imminent (Squat instead!)