Introduction
Early recognition of lightning when it is approaching is
the best defense. It is very important to be able to monitor
how far away the lightning is. All outdoor activities such
as swimming, camping, hiking, should be stopped and safety
should be sought when the lightning is within 6 miles. Wait
a minimum of 30 minutes for this storm to pass.
What do you do when lightning is near?
Lightning can never be prevented, but you can reduce your
chances of being struck by:
- Avoiding high ground, water, solitary trees, open spaces,
metallic objects. Search for low ground, ditches, trenches.
If they contain water or if the ground is saturated, then
find clumps of shrubbery or trees, all of uniform height.
- Remove all metal objects, bracelets, watches, rings,
if possible. It is best to crouch down on the balls of your
feet with your hands over your ears. There should be at
least 20 feet between you and other people. Do not all huddle
together.
- If you are in a fully enclosed metal automobile, seek
refuge with all the windows rolled up and your hands in
your lap.
- Avoid all metal shelters and sun shelters. If golfing,
put down the clubs and get off the golf course.
- Stop all bicycles and motorcycles and get away from them.
How to handle lightning victims:
- Seek medical attention as soon as possible. If necessary,
begin CPR. Make sure before doing CPR that the person absolutely
is not breathing or there is no heart rate before starting
resuscitation. Victims DO NOT retain an electrical charge.
They are safe to handle. Check for burns along the extremities
and around areas. Treat the burns the same as other types
of burns. Please see Burn Section in Survive outdoors.
Very common after effects:
- Short, but not long term impaired eyesight
- Loss of hearing
What is lightning?
Lightning is a form of electrical discharge between clouds
or between clouds and the ground. The discharge may take place
between two parts of the same cloud, between two clouds or
between a cloud and the ground. Thunder is the sound waves
produced by the explosive heating of the air and the lightning
channel during the return.
Some specifics:
- Most lightning strikes occur either at the beginning or
the end of a storm.
- Average lightning strike is 6 miles long.
- Lightning reaches 50,000 degrees farenheit, 4 times as
hot as the sun's surface.
- A cloud to ground lightning channel can be 2-10 miles
long.
- Voltage in a cloud to ground strike is 100 million to
one billion volts.
Other facts:
- Lightning is the most dangerous and frequently encountered
weather hazard people experience each year.
- Lightning affects all regions. Florida, Michigan, Pennsylvania,
North Carolina, New York, Ohio, Texas, Tennessee, Georgia
and Colorado have the most lightning deaths and injuries
every year.
- Lightning is the #1 cause of storm-related deaths.
- Damage costs from lightning are estimated at 4-5 billion
each year in the U.S.
- Around the earth, there are 100 lightning strikes per
second or 8 million, 6 hundred and 40 thousand times per
day. What is commonly referred to as heat lightning is actually
lightning too far away to be heard. However the storm may
be moving in your direction.
- There are approximately 100 thousand storms in the US
each year.
Lightning strike statistics
- Americans are twice as likely to die from a lightning-related
death than from a tornado, hurricane or flood.
- The Federal Emergency Management Agency (FEMA) estimates
there are 200 deaths and 750 severe injuries from lightning
each year in the US.
- 20% of all lightning victims die from the strike.
- 70% of survivers will suffer serious long-term affects.
- Annually there are more than 10,000 forest fires caused
by lightning.
Who's at risk?
- 85% of lightning victims are children and young men age
10-35 engaged in outdoor recreation and work activities
outside.
- 70% of all lightning injuries and fatalities occur in
the afternoon.
- Most lightning deaths involve people working outdoors
and engaged in outdoor recreation.
- Lightning in remote terrain creates dangerous conditions.
Hikers, campers, backpackers, skiiers, fishermen, and hunters
are especially vulnerable when they participate in these
activities.
- Many survivers of lightning strikes report that immediately
before being struck, their hair was standing on end and
they had a metallic taste in their mouth.
- Long-term injuries from lightning strike can include
memory and attention loss, chronic numbness, muscle spasm,
stiffness, depression, hearing loss and sleep disturbance.
Treatment of Lightning Injuries
Lightning injuries are most common in areas of frequent thunderstorm
activity. For example, Florida has 70-90 thunderstorm days
per year throughout the state, Northeast and Mexico 70 thunderstorm
days per year, and Southern Arizona 60 thunderstorm days per
year. There really is no accurate reporting method of thunderstorm
deaths/lightning injuries in the U.S. However lightning strike
deaths are estimated at between 50 and 300 per year in the
U.S. A Colorado study from 1950-1991 reported that 89% of
fatalities were single fatality mishaps, 10% were 2 fatalities
per lightning strike, and 1% were 3 or more fatalities per
incident. This probably reflects the availability of bystanders
to provide emergency care at that time.
A lightning bolt is only 6-8 cm in diameter, carrying between
10 and 100 million volts in 20 to 50 thousand amps of direct
current. The duration is approximately one millisecond. Volts
of 2 billion and 500 thousand amps have been measured in the
past.
Lightning bolts can strike up to 10 kilometers
in front or behind a thunderstorm cell.
A "bolt from the blue sky" is a real entity and
is responsible for many strikes on people per year. Thunder
travels at the speed of sound. A lightning flash travels at
the speed of light. Speed of light is approximately 186,000
miles per second.
Types of Lightning
- Streak lightning which is the most common.
- Ribbon, usually seen in cloud-to-cloud lightning.
- Bead lightning - Persistent lightning that is actually
an optical afterimage.
- Ball lightning - Very rare, where there is a cluster
or ball of lightning. This is rarely seen.
Lightning does not usually enter the body, but flashes over
the exterior. Some charges may leak into the body via the
eyes, ears or mouth.
Burns are usually superficial, and usually caused by the
heating up of objects close to the skin, belt buckles, bracelets,
rings. It is not uncommon to not have severe burns.
Clothing can be blasted from the body.
THERE IS NO RESIDUAL CHARGE IN THE BODY
AFTER A STRIKE. IT IS OKAY TO TOUCH THE VICTIM. BELIEVING
OTHERWISE IS A MYTH.
Minor injuries associated with lightning strikes:
- Confusion.
- Temporary blindness.
- Temporary deafness.
- Amnesia.
- Numbness in the extremities.
- Rupture of the eardrum.
- These victims usually recover with no serious problems.
Moderate injuries associated with lightning strikes:
- Combative.
- Disorientation.
- Possibly some paralysis.
- Loss of consciousness.
- Coma.
- Victims usually recover; however they have some significant
side-effects afterwards.
Severe injuries associated with lightning strikes:
- Cardiopulmonary arrest.
- Direct brain damage.
- Blunt trauma to the brain.
- Blunt trauma to internal organs.
Prognosis is poor.
- Cardiopulmonary arrest can be a primary event and CPR
needs to be started within a few seconds. However with animal
studies, it has been shown that respiratory paralysis lasts
longer, leading to secondary hypoxic cardiac arrest, which
means the heart stops due to not enough oxygen to the body.
- Neurological injuries: These can vary. There are invariably
fatal. Blood pressure instability is very common and can
last for several days.
- Burns: Usually superficial; however deep burns are an
indication of electrical passage through the body and carry
a very poor prognosis. Burns also occur around metal objects
that are on the body and feathering burns are not really
burns at all. They are due to the intense shower of electrons
across the skin from the lightning strike.
Other injuries that can occur after a lightning strike include:
- Cataracts which can develop very rapidly, within days
to weeks, or show up years later.
- Eardrum rupture is also very common.
Treatment of the lightning strike victim:
- Lightning does strike twice in the same place. So remove
the victim as soon as possible.
- CPR should be started immediately if the criteria are
met.
- Transport the victim as soon as possible to an emergency
department.
- If multiple victims are down, reverse triage is important.
People that are able to talk, move or otherwise show significant
signs of life will likely survive. Do not approach those
victims first. Victims that are down that are in obvious
need of CPR should be tended to first. Patients obviously
in cardiac arrest get transported first. Please do use appropriate
spinal precautions.
Some basics about how NOT to get hit by lightning:
- Don't be the tallest object in the area.
- Stay off ridgelines and mountaintops.
- Don't be next to the tallest object in the area.
- Remember that a storm approximately 10 miles away can
reach out and touch you.
- If you are in the mountains, shelter in a grove of trees
staying low, or in a region of rolling hills and staying
low are also an options.
- If in a group, please spread out so that a single strike
will not affect all of you.
- Shelter in a metal vehicle is relatively safe.
- On a golf course, you clearly more safe in a cart than
under a tree.
- Bolts can be conducted through tree roots, telephone
lines, water pipes, electrical wires, cable TV lines, computers,
steel reinforcement rods and concrete.
- Stay out of the bathtub.
- Stay out of the shower.
- If caught out in a completely open area, laying flat
is not a good idea. Crouching down with feet together is
as good a posture as any, as well as hands over your ears.
However this is a very hard position to sustain.
- Stay off all bodies of water in thunderstorm conditions.
To increase your safety and as a precautionary measure, it
has been shown that the lightning strike detector Survive
Outdoors has to offer on this web site can decrease the likelihood
of being struck by lightning. The lightning strike detector
alerts you to lightning that is within close proximity, which
allows you the necessary time to seek shelter before you are
in harm's way.
Survive Outdoors would like to acknowledge a portion of the
above information. We therefore cite at this time Robert C.
Allen, D.O., F.A.C.E.P., Colonel, United States Air Force,
USAF School of Aerospace Medicine, Brooks Air Force Base,
Texas.