The Evidence on Lightning Safety, Without the Hype

Key takeaways

• Rule of thumb: when thunder roars, go indoors
• Safe shelter: an enclosed building with plumbing and wiring, or a hard-topped metal vehicle with windows closed
• Most useful single change: Check the forecast before outdoor activities and plan where you will shelter.
• Commonest mistake: Sheltering under a tree.
• See a doctor if any of the signs under "When to speak to a doctor" below apply to you.

What it is

How to protect yourself from lightning during thunderstorms. It sits within Weather Safety. Below are the published figures, in one place.

The numbers, in one place

What helps

The advice below comes straight from the guidance cited at the foot of this page.

• Check the forecast before outdoor activities and plan where you will shelter
• Head indoors as soon as you hear thunder
• Stay off corded phones and away from plumbing and electrical equipment during a storm
• Learn CPR so you can help someone who has been struck

What to avoid

What to steer clear of, and why it catches people out.

• Sheltering under a tree
• Staying in or near water during a thunderstorm
• Returning outside as soon as the rain stops

In depth

Lightning is a giant electrical discharge between a storm cloud and the ground or within clouds. It can strike miles away from the storm itself, sometimes appearing to come out of a clear sky, which is why there is no safe place outdoors once you can hear thunder. Most lightning victims are not caught by surprise in the middle of a storm; many are struck before the rain arrives or after it ends, when they think the danger has passed.

Only a small share of injuries come from a direct strike. More often, the current spreads through the ground and up into a person nearby, jumps from a tree or object to someone standing close to it, or travels through wires, pipes or metal fences. This is why sheltering under a tree or in an open pavilion is unsafe: they attract the strike and the current can spread to anyone underneath or nearby.

Lightning's biggest immediate danger is to the heart and breathing. A strike can stop the heart and the breathing center in the brain. The heart sometimes restarts on its own while breathing does not, so rescue breaths and CPR can save lives. Most people survive lightning strikes, but many live with long-term effects such as memory problems, chronic pain, hearing loss or mood changes, which may not be obvious at first.

Signs and symptoms

• Thunder you can hear, which means lightning is close enough to strike you
• Darkening skies, rising wind and a building thunderhead cloud
• Hair standing on end or a tingling feeling on the skin, a sign a strike may be imminent
• In someone struck: unconsciousness, confusion or not breathing
• Fern-like red patterns on the skin, burns, or temporary paralysis of the legs or arms
• Ringing ears, hearing loss or vision problems after a strike

Causes and risk factors

• Being outdoors during thunderstorms, especially in open areas
• Activities such as fishing, boating, camping, hiking, golf and field sports
• Outdoor work in construction, farming and landscaping
• Being near tall, isolated objects such as trees, poles or towers
• Contact with water, plumbing, wired phones or electrical equipment during a storm
• Waiting too long to seek shelter, or returning outside too soon

How it is checked

Anyone struck by lightning should be checked in an emergency room, even if they seem fine, because some injuries are hidden. Doctors check the heart with an electrocardiogram and blood tests, look for burns and injuries from being thrown, and examine the eyes and ears. A person may have had their eardrums ruptured or developed injuries to the spine or head.

Some effects only appear later. Cataracts can develop months after a strike, and problems with memory, concentration, sleep, pain or mood can emerge or persist long term. Follow-up with your primary care doctor, and referrals to eye, hearing, neurology or mental health specialists, can help identify and manage these.

Treatment and support options

Helping someone who has been struck

Make sure you are safe first; the storm may still be active, so move the person to a safer location if needed. Call 911. Lightning victims do not carry a charge, so it is safe to touch them. If they are not breathing or have no pulse, start CPR and use an AED if one is available. If several people are struck, help those who appear lifeless first, since others are likely to be breathing.

Hospital care

Hospital treatment depends on the injuries. Doctors may monitor the heart, treat burns, manage broken bones or head injuries, and check for damage to muscles and kidneys. Temporary paralysis or numbness of the limbs often improves within hours. Most survivors go home after a short stay.

Long-term recovery

Survivors may face lasting effects such as chronic pain, headaches, memory problems, fatigue, sleep disturbance, anxiety or depression. These can be frustrating because they are not always visible. Rehabilitation, counseling and support groups for lightning survivors can help. Tell your doctor about any ongoing symptoms so they can be properly assessed.

If you are caught outside

There is no truly safe position outdoors, but if you cannot reach shelter, avoid open fields, hilltops, water and tall isolated objects. Move to lower ground away from metal fences and power lines. If you are in a group, spread out so that a single strike does not injure everyone. Keep moving toward safe shelter.

Prevention

• Set a plan with your group for where to go and when to stop activities
• Know that cars with hard metal roofs offer protection, but convertibles and open vehicles do not
• Postpone outdoor plans when thunderstorms are forecast
• Unplug sensitive electronics before a storm rather than during it
• Use lightning detection apps or alerts during outdoor events

Day to day

Many people who live or work outdoors in thunderstorm-prone areas build lightning safety into their routine. Check the forecast every morning in summer, plan outdoor tasks for times when storms are less likely and know where the nearest safe building or vehicle is. Coaches, camp leaders and event organizers should have a written plan that names who calls a halt and where everyone goes.

For survivors, living with the aftermath may take time. Symptoms such as memory lapses, irritability or chronic pain can affect work and relationships. Keeping a symptom diary, sharing information with family and seeking care from professionals who understand lightning injuries can make a difference. Talking with other survivors can be reassuring and help you feel less alone.

For specific groups

Outdoor workers

Construction, farm, utility and landscaping workers are often far from shelter. Employers should monitor weather and have clear rules about stopping work when thunder is heard. Workers should know where to go and not wait for permission if thunder is close.

Athletes and coaches

Sports fields are open areas with few safe places. Coaches and officials should suspend play at the first thunder and wait 30 minutes after the last thunder before resuming. Dugouts, bleachers and open-sided shelters are not safe places to wait.

Boaters and swimmers

Water offers no protection, and boats are often the highest point around. Get off the water as soon as storms threaten. If you are on a boat with a cabin, stay inside and avoid touching metal or electrical equipment.

Questions to ask your doctor

• What tests do I need after being struck by lightning?
• Could my memory or concentration problems be related to my strike?
• Should I have my eyes and ears checked, and how often?
• What can help with the chronic pain or headaches I have had since?
• Are there specialists or support groups for lightning survivors?
• Is it safe for me to return to outdoor work or sports?

More questions, answered

Is it true that lightning never strikes the same place twice?

No. Lightning often strikes the same place repeatedly, especially tall structures such as towers and tall buildings. It can also strike the same area several times during a single storm.

Are rubber tires what protect you in a car?

No. A hard-topped metal vehicle protects you because the metal body carries the current around the outside and into the ground. The tires make little difference. Keep windows closed and avoid touching metal parts during a storm.

Can I shower during a thunderstorm?

It is best to avoid showering, bathing or washing dishes during a thunderstorm. Lightning can travel through metal plumbing and water inside a building. Wait until the storm has passed.

How far away can lightning strike?

Lightning can strike several miles away from the storm that produces it. If you can hear thunder, you are close enough to be struck, even if the sky above you looks clear.

Is the lightning crouch still recommended?

It is no longer taught as a way to stay safe, because it offers little real protection. Getting to a safe building or hard-topped vehicle is the only reliable approach. If you are truly caught in the open, avoid high ground and water and keep moving toward shelter.

Can lightning come through a phone?

Yes, a corded landline phone can carry current from a strike on the phone line. Cordless phones and cell phones are generally safe to use indoors, as long as they are not plugged in to charge.

Related topics

• CPR and Defibrillation: What the Evidence Actually Says (Emergency Care)
• Hearing and the Brain: Sorting the Evidence From the Noise (Brain Health)
• What the Guidance Really Says About Opioid Overdose and Naloxone (Substance Use and Recovery)
• What the Guidance Really Says About Air Pollution and the AQI (Environmental Health)

Where to go next

• Popular Beliefs About Lightning Safety, and What Is Actually Published
• Lightning Safety: A Beginner-Friendly Start
• Lightning Safety — the reference entry
• Weather Safety: The Complete Guide
• What the Guidance Really Says About Flood Water Safety
• What the Guidance Really Says About Older Adults and Extreme Weather

When to speak to a doctor

Call 911 right away for anyone struck by lightning. If they are not breathing or have no pulse, start CPR and use an AED if one is available.

Where this comes from

• CDC — Lightning Safety
• American Red Cross — Thunderstorm Safety

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.