Know What Can Kill You: Venomous Snakes, Dangerous Plants, and What to Do When It Goes Wrong
Snakebite myths like tourniquets and cut-and-suck make things worse. Here is what to actually do, where to find antivenom, and how to identify local species.
Preparedness is mostly about systems and supplies and community. But some of it is simply about knowing what is around you. The land you live on, hike through, garden in, or might be moving across during a disruption has its own hazards, and a significant number of them are biological. Most are avoidable with basic knowledge. Some of them, if encountered at the wrong moment and handled incorrectly, can kill you or someone you care about.
This post is not a complete field guide. It is a framework for thinking about biological hazards in your local environment with a deep focus on venomous snakes, because they are among the most misunderstood, most feared, and most dangerously mismanaged hazards most people in the United States are likely to encounter.
Plants Worth Knowing
Before getting to snakes, a brief note on plants, because toxic plant exposure is far more common than snakebite and significantly underappreciated as a preparedness concern.
Several categories of dangerous plants are widespread in the United States. Contact hazards like poison ivy, poison oak, and poison sumac cause severe dermatitis and are almost universal across the country. Giant hogweed, less common but present in parts of the Northeast and Midwest, causes phototoxic burns that can be severe and permanent. These are identification problems: you need to know what these plants look like and teach the people around you to recognize them.
Ingestion hazards are more varied. Water hemlock is one of the most toxic plants in North America and is often mistaken for edible species. Pokeweed, which many people recognize from its distinctive berries, is toxic at multiple life stages. Jimsonweed, nightshade, and several species of mushroom round out a list of plants and fungi that people have died from after misidentifying them as edible or medicinal.
In a disruption scenario where foraging becomes a real consideration, the gap in botanical knowledge in most households is significant and worth closing before it needs to be applied. A regional field guide to edible and toxic plants, specific to your geography, belongs in every preparedness library. Peterson Field Guides and the Audubon Society series are reliable starting points.
The Snake Problem
Snakes are where biological hazard preparedness gets both most important and most contaminated by mythology. The mythology is genuinely dangerous because it shapes how people respond to bites, and the wrong response can accelerate envenomation, cause additional tissue damage, delay appropriate treatment, and in some cases kill someone who might otherwise have survived.
The United States has two medically significant categories of venomous snakes: pit vipers and elapids.
Pit vipers include rattlesnakes, copperheads, and cottonmouths (water moccasins). They are named for the heat-sensing pit organ between the eye and the nostril that helps them locate warm-blooded prey. Pit vipers account for the vast majority of venomous snakebites in the United States. Copperheads are responsible for more bites than any other species and are widespread across the eastern and central United States.
Elapids in the United States are represented by coral snakes, found primarily in the Southeast and parts of the Southwest. Coral snake venom is neurotoxic rather than hemotoxic, affecting the nervous system rather than blood and tissue. Coral snake bites are far less common than pit viper bites but are medically serious for different reasons, and the treatment is different.
Know Your Local Species
The single most useful thing you can do as a preparedness measure related to snakes is learn to identify the venomous species that actually live in your region. This sounds obvious. It is consistently skipped.
Most people cannot reliably distinguish a copperhead from a harmless species in the field, which leads to two problems. They misidentify nonvenomous snakes as venomous and either kill them unnecessarily or panic unnecessarily after being bitten by one. And they misidentify venomous snakes as harmless and handle them or delay treatment after a bite.
The triangular head and elliptical pupil heuristics that circulate widely are unreliable. Many harmless snakes flatten and widen their heads when threatened. Some harmless species have pupils that appear more elliptical than round depending on lighting conditions. Pattern mimicry is real: milk snakes and scarlet king snakes are often mistaken for coral snakes, and the red-touches-yellow mnemonic is not universally reliable across the full range of coral snake subspecies.
Learn your specific regional species by name and appearance. The Facebook group Wild Snakes: Education and Discussion is a well-moderated community for exactly this purpose, covering identification across all species and regions. A printed field guide to reptiles specific to your state or region, kept at home and consulted regularly, is worth more than any mnemonic.
If you are in the southeastern United States, Snakes of the Southeast by Whit Gibbons and Mike Dorcas is a well-regarded regional identification reference. For snakebite response specifically, a practical guide on what to do between the bite and the hospital is available. Equivalent identification guides exist for most regions of the country.
What to Do When Someone Is Bitten
This section is the most important part of this post because it is where the mythology causes the most damage. The wrong response to a venomous snakebite is not just unhelpful. It is actively harmful.
The correct response is simple: stay as calm as possible, remove jewelry and tight clothing from the affected limb before swelling begins, keep the bite site above (ideally 60º above) the level of the heart, get to a hospital with antivenom as quickly as possible, and do not do any of the things listed in the next section.
Time between bite and antivenom is the primary variable that determines outcome. Everything else is secondary. Call ahead to the receiving hospital if possible. Emergency dispatch can help route you to a facility that stocks the appropriate antivenom.
Note as much as you can about the snake if it is safe to do so: size, color pattern, head shape, whether it was a strike from a defensive posture or active pursuit, although the antivenom for all North American pit vipers is the same: CroFab or ANAVIP. Do not attempt to capture or kill the snake for identification. This causes a significant proportion of secondary bites. A photograph taken from a safe distance is acceptable if it does not delay departure, but knowing native species and if any elapids are present should be sufficient.
Monitor for symptoms during transport: pain and swelling at the site, which is typical for pit viper bites; numbness or tingling around the mouth or face; nausea; difficulty breathing; weakness. Report these to medical staff on arrival.
For most pit viper bites, antivenom within several hours produces significantly better outcomes than antivenom at twelve or twenty-four hours, but the latter still produces better outcomes than no antivenom at all. Even several weeks out, it has been observed to help when there's still evidence of venom circulating or if there is re-envenomation from swelling going down and pockets of venom being released.
What Not to Do
This list is not academic. Every item on it has caused additional injury or death.
Do not apply a tourniquet. Pit viper venom causes local tissue necrosis. Concentrating it in one area by cutting off circulation accelerates tissue destruction. Tourniquets applied to snakebite victims have resulted in amputations that would not otherwise have been necessary.
Do not cut and suck the wound. This does not extract meaningful amounts of venom. It introduces bacteria into the wound, which is already compromised tissue. It can expose the person performing it to venom through mucous membranes if they have any oral injuries. It has been definitively debunked by emergency medicine and toxicology. Do not do it.
Do not apply ice or cold packs. Cold application constricts blood vessels, concentrates venom in the tissue, and worsens local tissue damage. It also delays swelling, which can mask the progression of envenomation from the treating physician.
Do not apply electric shock. This appears in older survival literature and has no basis in evidence. It does not deactivate venom proteins. It does cause electrical injury.
Do not drink alcohol. It is sometimes suggested as a sedative or pain management measure. Alcohol dilates blood vessels and accelerates venom distribution.
Do not try to identify the snake by handling it. Dead snakes can still envenomate through a reflex bite for up to several hours after death.
Do not wait to see if symptoms develop before going to the hospital. Some envenomations have a delayed onset of systemic symptoms. By the time systemic symptoms are apparent, the window for optimal antivenom response may have narrowed.
Antivenom: Where to Find It
Antivenom is the treatment. It is the only treatment. Everything else is supportive care.
CroFab (crotaline polyvalent immune Fab) is the primary antivenom used for pit viper bites in the United States. ANAVIP is an alternative for rattlesnake bites specifically. Coral snake antivenom has a more complicated supply situation: the product manufactured by Wyeth was discontinued, and availability of coral snake antivenom can vary significantly by region and facility. It’s often not a case of it being rare, but more a question as to whether the treatment facility has any on hand due to infrequency of use. University of Florida is the only place that stocks animal coral antivenin.
The practical implication: if you are in a region where coral snakes are present, it is worth knowing in advance which hospitals in your area stock coral snake antivenom. This information is not always obvious from outside and is worth a phone call to your regional poison control center.
The national Poison Control Center hotline is 1-800-222-1222. They are available twenty-four hours a day and can provide real-time guidance on snakebite management, route you to appropriate facilities, and communicate with treating physicians.
The National Snakebite Support organization maintains resources specifically for snakebite victims and their families, including guidance on treatment, hospital routing, and managing the financial and medical aftermath of serious envenomations. They have a Facebook support group. The Snakebite Foundation covers education, research, and advocacy around snakebite treatment and prevention.
The Preparedness Connection
In a normal infrastructure environment, the response to a venomous snakebite is: call 911 or drive to the nearest emergency department. The system handles the rest.
In a disruption scenario where emergency services are overwhelmed or unavailable, the calculus changes. The window for antivenom is not infinite, but it is also not as narrow as popular mythology suggests. For most pit viper bites, antivenom within several hours produces significantly better outcomes than antivenom at twelve or twenty-four hours, but the latter still produces better outcomes than no antivenom at all. Knowing in advance which hospitals in your region are most likely to stock antivenom, and how to get there under various infrastructure conditions, is part of the preparedness planning that this series has been building toward.
It is also worth knowing what not to do in the hours between bite and treatment, because the interventions that people instinctively reach for, the tourniquet, the cut and suck, the ice pack, are the ones most likely to make the outcome worse. The best thing most people can do in that window is keep the patient calm, keep the bite site above heart level (ideally at 60º), and move toward treatment as quickly as conditions allow.
Know what lives near you. Know what it looks like. Know what to do and what not to do. That is the whole framework, applied to one of the more common biological hazards most people in the United States are likely to encounter.
