Wilderness Survival Rules of 3 – Air, Shelter, Water and Food

survival horse

Scared, unprepared trail riders actually thought they would need to eat their horse on their 1st survival night!

Those who venture into the great outdoors should, at a bare minimum, know the survival rules of three.

A friend told me a story about getting lost with a dozen people and horses on a horseback trip in the Appalachian mountains. They were only lost for a short time, but could not get back to the trail head before dark, so they had to spend the night on the trail. They were not prepared to spend the night, so they were tired, miserable and hungry. But the Summer weather was forgiving, so as long as they had water, as long as nobody was missing critical medications and nobody got injured, they were never in any real danger.

A common theme to survival situations is that people find themselves in a place and at a time they didn’t expect, and that is exactly what happened to these ill-prepared trail riders. They were guilty of making the assumption that they would get back to civilization before dark and only planned accordingly. They didn’t have extra food, most didn’t have clothes for night time temperatures and not a single person had a flashlight.

As I remember the story, one guy had plenty of beer stuffed in his saddle bags, several guys had hand guns and several more had cigarettes, but more importantly, they had cigarette lighters.

The part of the story I found most interesting was that some people were talking about killing and eating a horse the first night. Knowing how attached horse people are to their horses, I laughed when I heard this and assumed my friend was joking. They assured me they were not joking and that some of these people were really concerned about dying from hypothermia at night if they didn’t eat.

Hard to believe. Sure, calories in the belly will help generate heat, but you can’t eat enough to stay warm if you aren’t sheltered from the cold. How could someone really get the priorities for survival so wrong?

Survival Rule of 3 and Survival Priorities

For real survival situations it is better to remember and prioritize by the four levels of the Survival Rules of 3:

  • You can survive for 3 Minutes without air (oxygen) or in icy water
  • You can survive for 3 Hours without shelter in a harsh environment (unless in icy water)
  • You can survive for 3 Days without water (if sheltered from a harsh environment)
  • You can survive for 3 Weeks without food (if you have water and shelter)

The main point of the Rules of 3 that we have to concentrate on the most immediate problem first. I am mainly thinking about survival in an outdoor/wilderness context, but  a survival situation is a survival situation no matter when or where it occurs and these rules/points/priorities are still applicable. There is no need to think about food if the main threat to your survival is hypothermia because your clothes are wet. And make no mistake, if you are shivering and can’t get dry and warm, you may not able to function after three hours. If you are alone, you may have only about three hours to live.

Lets look at the first two situations (3 minutes without air and 3 hours without shelter),  which are the two most common survival situations people can encounter because they require immediate attention and because time is limited, you may not be able to count on anyone to rescue you in time.

You Can Only Survive for Three Minutes Without Air

Obviously, any condition that threatens breathing (or the blood’s ability to circulate Oxygen) is an immediate survival situation and anyone that has asthma or allergic reactions has to be alert and constantly prepared and never go anywhere without an inhaler or emergency epinephrine or anything else your doctor has prescribed. You should also carry a medical identification card or wear a medical identification bracelet that tells others about your allergies.

When I was a kid, a several families were having a cook out. The kids were playing and the adults were sitting in the shade just doing what people do. One guy that was drinking soda from a bottle didn’t notice that some kind of bee or wasp had crawled inside his bottle. As he took the next drink, he swallowed the bee which stung him inside the throat. His throat started swelling and in a matter of minutes, he was having a very hard time breathing. Somebody called for an ambulance, but quickly decided there wasn’t enough time to wait, so they put him in the car and took off down the road to meet the ambulance. The paramedics were able to open his airway and also gave him epinephrine to counteract the anaphylaxis. I remember my father saying he was glad he didn’t have to do an emergency tracheotomy (cricothyroidotomy).

Until 12/31/2011, there were epinephrine inhalers that could be purchased without prescription, but they are no longer available due to the propellants that supposedly deplete the ozone layer. Now all epinephrine injectors and inhalers require a prescription.

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Basic Survival Preparedness Items:

I have a good friend who lost his sister because she choked to death on a piece of steak. She was eating with friends, but none of her friends were successful using the Heimlich maneuver and none thought to attempt an emergency tracheotomy. The young woman died on the floor right in front of them. They all claimed to be sober and drug free. You can try giving yourself the Heimlich Maneuver by bending over a hard surface like a chair, counter top, log or large rock. Otherwise, you are at the mercy of your companions. If I were choking, I would hope my friends would also try even a crude tracheotomy before letting me die.

How To Perform the Heimlich Maneuver

Perhaps one of the best things we can do is to make sure we have first aid training so we can help others and to make sure the people we spend the most time with are also trained, so they can help us if needed. Remember, may all hope to be heroes, but we always fall to our lowest level of training in an emergency. As Denzel Washington said in the movie “Man on Fire”, “You are either trained or not trained”. Are you trained?

How To Perform CPR

You Can Only Survive Three Hours Without Shelter

As long as everyone was breathing okay, our lost trail riders first priority should have been to make sure that no one in the group was in danger from exposure to cold or heat.  They all survived the night because the weather was good and they were able to build a fire. If they were caught in the rain or if anyone had fallen in the creek and they weren’t able to build a fire, things might not have turned out as well. It is also a good thing they were at 3,000 foot mountains and not at 9,000 feet.

survival rule threes shelter

Having proper shelter is a top survival priority.

Several years ago about 25 miles from here, two people on vacation went out for an afternoon hike above 9,000 feet on a beautiful September day. They didn’t tell anyone where they were going and they evidently ignored advice from someone who claimed they were told to take more clothes in case the weather changed. The weather did change, the clouds rolled in, visibility decreased and it started snowing. Nobody knew they were missing until their plane arrived in Atlanta without them 5 days later. Their bodies were found the following Spring.

Nobody knows for sure what happened, but they must have been cold and wet. They did not get back to their vehicle and they must not have been able to build a fire. Perhaps warmer clothes and/or rain gear could have bought them more time to find their way to safety. A fire would have bought them more time, but you can’t move and sit by the fire at the same time. A PLB (Personal Locator Beacon) device would have brought the cavalry on the run, but they were probably already dead before morning.

Deaths From Blocked Airway and Exposure to Heat and Cold

Most of us probably never think about finding ourselves in any of these survival situations, but according to the best sources I can find, it is more common than you might think. Over 8,000 people die in the U.S. each year from not being able to breathe. That includes choking (4,600; National Safety Council), asthma (3,300; AAAAI.org), food allergies (150-200; AAAAI.org) and bee stings (40; AAAAI.org).

In addition, an average of 1,028 people die from exposure to cold or heat each year in the U.S. According to IDC10data.com (5,811 people died from hypothermia associated from “Exposure to excessive natural cold” between 1999-2007 and 3,441 deaths were from “Exposure to excessive natural heat”).

What Else Do You Need to be Prepared?

Before heading out, we should all ask ourselves what other gear, medicine, food or water would we throw in the packs if we knew we wouldn’t get back before dark ? Before midnight? Before sunrise tomorrow morning? Remember that you may be making a huge assumption if you think getting back to your car is getting back to civilization. This is survival 101. Obviously, the list quickly grows larger and larger and we can’t always pack enough food and water for 3 or 4 days.

Before you get yourself into a situation that you need someone to help to get you out, the most important thing you could do is make sure that someone knows where you are going and when you will be back. If they don’t know you are missing, they can’t look for you. After several days, someone might realize you are missing, but they will not know where to start looking.

Now, I always include a PLB in my survival gear since my niece was injured in a snow machine accident (read my I wish I had a PLB story) and anyone that spends time in the backcountry should too.

More Survival and Preparedness items:


  1. SurvivAllExpert says

    I always carry Frog Toggs with me, winter or summer. They are super lightweight, wind and water proof and are made of a material similar to tyveck that we applied as a weatherproof barrier for houses in Alaska before applying the siding. I’ve been out in -20 with 40 mile winds and the Frog Togg outers, with layers of fleece inside, kept me warm and toasty while allowing me to do chores. They only cost around $20 for a jacket top with hood and pant bottoms. I keep them in all of our families emergency bags. So far I’ve been the only one to use them but I have to say they are the answer to personal shelter in almost any short term crisis.

    • Backcountry Chronicles says

      Good Advice. Better to have it and not need it than need it and not have it. Good endorsement for Frogg Toggs. If you used them in -20°F and 40 mph, that is good enough for me. I removed your website link because too many links on that site do not work.

  2. Some smile about the 3-Years-Timespan. I dont:
    You can survive for 3 Years without Love (Human Contact)

  3. I’ve seen this all first hand. I also am in search and rescue. The 3 rule is a common thing but not real, but more of a scientific [academic exercise?] which is never close. I’ve fasted for 2 months for fun. 3 days without water just makes you really thirsty. Being in harsh weather varies there is no 3 hours on something without measure, it can be 3 minutes or 3 weeks depending on the weather. Also people can die far under par. It’s really all about your energy levels and how your body works and how much you abused yourself before the emergency.

    • Ranger: Thanks for the comments. I agree that the rule of 3 is not exact for every person under all conditions, but I am not sure what you mean by “but not real“. I added the [academic exercise?] comment to your comments in an attempt to clarify your statement. If that is not what you meant, let me know.

      No doubt, there are many cases where people survived longer than 3 weeks without food, 3 days without water, 3 hours without shelter and 3 minutes without air. Heck, there are people that can hold their breathe longer than 6 minutes. The whole point is to prioritize because of the magnitude of the threat. No point to worry about food when your most pressing threat is water or hypothermia. The emergency room doctor will not start cleaning and stitching a wound if your airway is obstructed.

      Fasted for 2 months for fun? That is hardcore.

      • Michael Berge says

        The 3 days without water is BS. In the desert, it can be as short as 3 hrs without water, even in the shade (ie shelter). The idea is you must figure out the greatest need and meet that need. Don’t get stuck on stupid sayings, that are not correct.

        • Obviously, 3 days without water assumes you have not crossed into the temperature range that puts you into the 3 hour zone. You can freeze to death in 3 hours too, which would make looking for food or water silly. Its about priorities or limiting factors. At that point shelter from heat would be highest priority. If that were not enough, then you are out of luck.

        • Justin Capp says

          It’s just a simple lesson on priorities relax man !!

    • Bruh, you’re a savage for not eating for 2 months. I wonder what’s the first thing you ate. (I know it’s unhealthy to do 2 months without food)

    • Really no food for 2 months, I call BS. You had to have snacked on something. You might not of had meals but you ate in order to keep your stamina. Did you mean you went 2 weeks maybe fasting?

  4. We don’t go to the woods without a small pack, waterproof matches, disposable lighter, rain gear (light pack-able), water filter, plastic sheet or lite tarp, area map, compass, small LED flashlight, and some high calorie food snacks and all the water you feel like carrying. This is our minimum list, for a 1 day foray, but will expand for a spike camp. Don’t forget cellphone, we have had coverage in places you would never guess. Sometimes a text will get through, when a call won’t.

    • Yes, we have just enough cell coverage to be dangerous. But remember to tell everyone to turn off the cell phones so they will have power if needed.

      • We used to keep them off, and on vibrate, but now we keep solar chargers in camp. We only use them to check up on the home front, it keeps the wives happy. Small price to pay for a couple of weeks of elk hunting!

        • No doubt a small price to pay to keep mamma from worrying. My wife thinks I’m too old to be out by myself, so I also never go into the backcountry without a PLB.

          I have a post here and the story about my niece breaking her leg on a snow machine. I will never be that helpless again.

          I am sure you have heard of some of these cases where people could have been saved or suffered less if they had a PLB as a backup.

  5. The rule of 3s makes perfect sense if one considers being prepared for the worst case. At 20 degrees below zero, you’ll be dead quickly with no water or shelter because it won’t be long until you’re too weak to help yourself. Even at 30 degrees above zero your life is in danger without shelter or proper attire. If you get wet your are really in trouble.

    Sure, you may survive longer than exactly 3 hours, but you won’t be able to do anything when you’re freezing to death. After some time you’ll get sleepy and that will be the end. Dehydration makes a person very weak and unable to do much. So does hypothermia. Sure, you may not die right at 3 hours or 3 days, but you will likely be too weak to do anything to help yourself, maybe even after 2 days or 2 hours depending on where you are and what you do. Better safe than dead. The precautionary principle.

    What really blows me away is how nonchalant and apathetic people are about water. When I talk to people around here about water, they look at me like I’m crazy. In 8 years of posting info on slow sand water filtration on my websites and blog, I’ve only had 30 or 40 questions about water filtration. Most people (in developed countries particularly) seem to take the availability of water for granted. Just turn on the faucet and there it is. Big mistake. One drink of bad water and you’ll likely be too sick to do anything.

    During a big emergency, there will be no bottled water at the “store”. In the wilderness, there’s no “bottled” water at the “store” or anywhere. Makes me sad for the unprepared.

    • Good points Dave. In the event of a catastrophe, there will be many victims because we are used to predictable supplies of water and power.

      I lived in a “developing” country for almost three years. I didn’t have a dependable water supply and there was no electricity, so I know what to expect. I also know how easy it is to get sick from bad water. You can’t take care of yourself, let alone try to go anywhere or do any work.

      I am not so sad for the unprepared, but you better believe the unprepared will look to the prepared for help when the water supply quits.

      I have also been working on a water filter. My fishing buddy showed me a duel bucket design he made. He has several in his house ready to use in case of an emergency. I always have a Lifestraw with me anytime I go hunting, hiking or fishing, but need something that can filter more water for the house.

    • I agree with you 100%, as I am in the process of trying to educate my community as well. I would love to hear about your sand water filtration system.

  6. Thank you for the heads up on the Lifestraw. A good thing to have.

  7. Tony Johnson says

    What about the other one?… 3 seconds without thinking.

  8. Do you do speaking gigs? We are looking for someone to speak to just such issues at our SPARC Event October 11, 2017. We don’t have speakers fees but can pay travel expenses, lodging and food.

  9. Love this. The first step for so many people looking at emergency preparedness or survival needs to be understanding how to simplify, prioritize, and get the foundation principles right. Definitely appreciate the fact you go into each one, talk about common sense items to encourage rescue, and fill the article out with more useful information. The Rule of 3 isn’t a law set in stone, but it’s a great starting point for anyone who wants to know more, and a great fallback for anyone who needs to stop and focus to survive. Good stuff – keep it coming!

  10. You are wrong about the air part. I can hold my breath easily for 3 minutes. There are free-divers that hold their breath for much longer than that on a regular basis.

    • Good for you meemo…
      Most people in survival situations can not. The point of this post is obviously not about exact times of survival for each individual, but for prioritization of risks…

      Can hold your breath for 3 minutes without any prep time?

  11. UR MUM NICE says

    What do you do when you are against BIG CHUNGUS

  12. You can survive for 3 Hours without shelter in a harsh environment? How in the world did cowboys spend months on the trail sleeping under the stars with a blanket and a campfire? I’m guessing that the men were of hardier stock back then than the Casper Milktoast 3 hour people of today.

    • Not sure why so many are taking the “Rules of 3” so literally. Should I change it to the rule of 3 (plus or minus 200%) and put some legalese in the fine print about based on person genetics, specialized training and current environmental conditions?

      “Rules of 3” are a generalization for prioritization. Do not worry about starving if you may die of hypothermia or heat first.

      Yes, our ancestors (including cowboys) could deal with harsh conditions based on their skills, simple technologies and acclimation. Perhaps a simple blanket and campfire is all the “shelter” needed to survive the night (comfortably or not). But you better believe they looked for better shelter in harsher conditions.

      Read Jack London’s short story “To Build a Fire” (2008 version)… A man with knowledge and skills of cold weather survival dies because of taking risks, then due to an accident.
      Did he die in 3 hours? Jack London didn’t say.

  13. Eric Cornell says

    I think the rule of threes is a tremendously useful mnemonic to help people order their priorities for preparing — and for reacting. Just for the heck of it, I was I was trying to come up with a “three second” rule, and came up with this: just in case you are tempted to solo climb up a steep cliff to get some food (and you don’t know what you are doing), remember to compare three-month food rule with the three-second fall rule — if you free-fall for more than three seconds, you won’t survive the impact at the end of it. Of course, the truth is you won’t be feeling really chipper after a 1.5 second free-fall, either, but as a way of prioritizing risks. It would be helpful to prioritize rapid blood loss, too, but it depends of course on _how_ rapid. In case of of very serious bleeding, one prioritizes stopping it even over restoring breathing. Maybe it could be put in terms of volume — an adult could lose three cups of blood suddenly, but not three pints, not so good.

    • Good points Eric. Seems like most rescues here in remote areas are due to people falling. And yes, assuming minimal wind resistance for a human body, 1.5 seconds of free-fall would be about 32 mph… 3 seconds about 64 mph. I don’t want to take either of those hits… And yes, serious blood loss can put someone in a bad way in just a few seconds. That’s all more reason for making good decisions when not close to help.

  14. Don’t forget the 3 seconds without wifi

  15. Hey this is so great thanks. So interesting. Perplexed as to why people are responding with.. “Oh I can hold my breath for more than three minutes” “oh I starved myself for fun for two months” .. . Good for you. Write your OWN blog about your personal greatest achievements of all time oh ye trumpet blowers.
    Loved the video on the Heimlich manoeuvre.

  16. I heard the rule of 3 many moons ago, and as a starting point to prioritise survival, it cannot be beaten.
    Good article.

  17. Patricia Padon says

    How to take care of food kept outside in 15 degree weather

  18. i hate this

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