3 Minutes Without Air | 3 Hours Without Shelter | 3 Days without Water | 3 Weeks Without Food
The amount of time will vary by person and situation, but the general guidelines above are good to memorize. Knowing how long we can stay active without clean air, shelter, water, and food and the consequences if we do not are the first steps to being better prepared for all of life’s surprises.
An adult can generally survive three days without water if they have shelter to keep their core body temperature regulated and to protect from severe weather. However, they can survive three weeks without food if they have enough water. The guidelines make some assumptions, but we will go over those below when we look at each need below.
Need: Air
Time: 3 Minutes
Risk: Lung and Brain Damage, Death
Brain cells can start dying in less than 5 minutes after their oxygen supply slows or stops, resulting in brain hypoxia, causing severe brain damage or death. Anyone who has tried to hold their breath for more than a minute knows that our body will tell us that something is wrong.
However, in many cases, the air quality we breathe can have just as severe consequences. If caught in a fire or a near collapsed building, the air can quickly fill with toxic particles. Even if one does get out safely, lung damage can be permanent without proper protective gear. Toxic particles can also travel quickly with the wind and remain harmful for miles, and even inhaling smoke for a short time can cause immediate effects.
An example of compromised air quality and long-term damage to the brain and lungs are the first responders and survivors of 9/11.
“… more than 70,000 patients are enrolled in the World Trade Center Health Program, and nearly 21,000 of them are specifically getting treatment for conditions caused by the toxic and hazardous air.” nydailynews.com
“Ten years after the WTC attack, lower respiratory symptoms (LRS) such as coughing, wheezing, trouble breathing, or using an inhaler still affected rescue and recovery workers, area residents and workers, and passers-by. Half of those with persistent LRS also had PTSD, depression, or generalized anxiety disorder.” nyc.gov
A more common example can be wildfires, such as those during August 2020.
“Across much of the Western United States, residents continue to endure the current wildfire season, which has firefighters battling nearly 100 large active wildfires that have already burned nearly 5 million acres. And where there’s fire, there’s smoke that blanketed several western cities this week.” - health.mil
Need: Shelter
Time: 3 Hours
Risk: Skin Damage, Difficulty Thinking, Hypothermia, Frostbite, Heat Stroke, Death
When the body cannot heat itself faster than it is cooled, it will use up its energy and restrict blood to where it is needed the most. If the body loses the ability to keep itself cool, the temperature can rise to 106°F in minutes. Either way, when the body cannot control the internal temperature, permanent damage can happen quickly.
Body temperature can drop dangerously low in just a few minutes if it is cold, raining, and windy; as the body gets very cold, it can affect the brain, making it difficult to notice until the damage has started. In the short term, this means shade from the sun, staying dry in the rain, and staying warm in the cold. In the long term, it means a place to sleep. Having the right clothes for the environment can help the body keep control of its temperature.
Learning to use supplies close at hand and using nature to provide minimal shelter will save time and energy. Tying a tarp to a tree and using rocks or something heavy to stake the tarp to the ground can provide shelter if caught outside in a sudden storm. It may not seem that one wall and no roof can make a shelter, but if that wall provides protection from the wind and reflects the heat of a fire, it can work for a night.
Learning to make a shelter with different materials takes time and practice. It is also not worth spending more time than is needed to provide shelter during a storm if one is not staying there overnight. What is essential is getting protection ready by sunset. An excellent shelter also provides security and safety from getting cuts and bites and needing to use a first aid kit.
Need: Water
Time: 3 Days
Risk: Dizziness, Dehydration, Death
Many variables affect the need for water, but an adult will need to have one gallon (3.8 Liters) per person per day on average for drinking and sanitation. When in a survival situation, consider the environment, activity level, body mass, and current hydration. The need for clean water is something that we as humans know all too well. Our body moves everything inside us around using water. When we do not get enough water, our blood also becomes thicker, making our heart pump harder, raising our blood pressure.
We can store water, boil it, treat it, or filter it, but we need water to live one way or another. It is also important to remember that there are very few clean natural water sources anymore, and one should never drink untreated water in nature. Drinking un-purified water can lead to vomiting and diarrhea, resulting in dehydration and death.
Need: Food
Time: 3 Weeks
Risk: Low Energy, Confusion, Dizziness, Death
The brain needs fuel to function correctly and causes difficulty in thinking and making plans. It may be the first thing we think of when planning for a survival situation, and while critical, it is not the most important. Furthermore, morale will only go down over time in a survival situation without a steady food source. Once sheltered and safe, it is essential to make plans within the first 8-16 hours.
“But what happens if I do not eat?” you might ask.
Well, in the first few days, here is what can happen with the body.*
*Starvation studies on humans are rare and are also a war crime, so source materials are not widely available. The information below is based on nutrition standards and studies of people who survived through starvation for different reasons.
12 Hours
- Depending on everyday activity level and the past few meals, the body will still have some food to turn into energy.
24 Hours
- The body will convert fat and muscle to energy, depending on body type and fitness level. Hunger pains will lessen, with fewer sharp pains, and feel more of a dull ache.
72 Hours
- After 72 hours, hunger pains are minimal as the body starts to adjust; mental function and critical thinking can become difficult even with adequate hydration.
- With a steady supply of clean drinking water, the body can adapt and use the stored energy available.
- Depending on fitness level, diet, and deficiency in any vitamins and minerals, after a few days to a week, lack of vitamins and nutrients will cause the body to work less efficiently.
Survival in any situation relies on these simple rules. Knowing how to prioritize these rules is critical. The ability to adapt to changing circumstances will empower you to stay alive. The way those needs are met will vary based on the situation, but the needs never change. Learning the basics is the first step to staying calm in disaster. Being prepared with the right plans and gear can help anyone remain adaptable in many situations. If you'd like to learn more about the pack we built for these situations, you can learn more about it here.