Snow Caves for Survival: Are They Safe?

Any time you are heading into cold regions or just dealing with the wintry season, making sure your winter survival skills are up to snuff is paramount if you want to be ready for emergencies.

More than any other factor, simple exposure is the single biggest and most consistent killer in a variety of outdoor survival scenarios, and is also one of the fastest.

Compared to heat, deep cold is far more likely to debilitate you and kill you rapidly.

This means you must have a plan for providing shelter for yourself and others in your group, no matter the setting and no matter the other circumstances. One of the best possible cold weather shelters is the snow cave.

Anywhere you have deep banks of snow to work with you can easily excavate and outfit a snow cave to protect yourself and others from the gnawing cold and blistering winds.

A properly designed and built snow cave can maintain livable internal temperatures even when outside temperatures are many degrees below zero.

This article will tell you everything you need to know about safely constructing and occupying these classic cold-weather shelters.

What is a Snow Cave?

A snow cave, as the name suggests, is a little more than a shelter excavated from a bank or hill of snow.

Compared to an igloo or a quinzhee which is constructed from compacted snow, a snow cave is created using the reductive method, with snow being removed from a built-up area to create an entrance and living space.

Snow caves have been around pretty much forever, and countless cultures throughout history have made use of them either as primary habitation or as emergency shelter when working, hunting, or voyaging through frozen lands.

Unsurprisingly, many species of animals make use of snow caves for dens and burrows since they are comparatively easy to construct and provide shelter without any other additions aside from their own design.

Snow caves are used today as emergency shelters by folks who know how to construct them and wind up getting trapped in cold, snowy environments.

They are also employed as dedicated habitation modules for research outposts, adventurers, hunters, and others who are going to be spending a considerable amount of time away from human habitation in the field.

The simplicity and adaptability of snow caves means that one can forgo carrying a considerable amount of shelter materials in the bargain so long as there’s plenty of deep snow to work with.

You might think that a shelter made out of some of the coldest stuff there is only going to chill you to the bone, but that isn’t true. Read on to see what makes a snow cave a snow cave.

Design Features

The most basic feature of a snow cave is that it is made entirely from snow, or rather excavated from snow, typically by digging into a large drift or bank of white stuff.

Generally, the main compartment should be higher than the entrance and entrance tunnel in order to allow cold or air to fall downward and seep out, keeping the living space significantly warmer.

This is most easily accomplished by digging at a slight upward angle into the snow in order to situate the main compartment higher than the entrance.

Lacking this capability, a trench or dugout can be installed in the main compartment to allow colder air to accumulate at the bottom of the space.

The main entrance tunnel should be at least 4 feet long, with 5 feet or longer being ideal if the snow is deep enough.

The entrance tunnel itself should only be as wide as necessary to allow entrance and exit for one person, no wider, to provide better insulation and protection from wind.

The best snow for constructing a snow cave is similar to the best snow for making snowballs, light, crunchy, but readily sticking together.

You should take pains to select a site that is free of rocks and other debris contaminating the snow, as this will make digging difficult and also poses the risk of compromising your structure.

To create the main compartment, a domed roof shape should be installed, which affords the best possible strength for the structure.

At all times, the snow that is forming the structural components of the cave such as the walls, roof, floor and benches for sleeping or sitting should be compacted to add strength and be at least a foot in thickness (after compaction).

Speaking of benches, these should be at least 16 inches off the floor of the cave to help keep occupants warm; remember that cold air sinks!

The end result is a reasonably spacious snow cave that will keep you dramatically warmer than the outside air.

Snow caves installed in frigid, sub-zero environments routinely maintain internal temperatures hovering right around freezing, 30° to 32° F (-1 -0° C), even while external temperatures plummet to more than -30° F(-34° C).

Constructing the Snow Cave

Before embarking on the excavation of your snow cave, understand that this is going to be much harder work than the childhood snowball fight for it you put together as a boy.

The use of tools is highly recommended, particularly snow shovels, ice axes, and any other implement that can help you excavate large quantities of snow at once.

Digging by hand should be avoided at all costs in order to prevent frostnip or frostbite. More on that in a minute.

You are going to work up a sweat doing this, and any readers who have followed this site for any length of time likely already know that sweaty bodies, wet clothes, and cold temperatures combine to make conditions perfect for hypothermia, which can strike in as little as a couple of hours.

You should expect the excavation of your snow cave to take anywhere from 3 to 4 hours as long as you have tools, good snow, and comparatively good conditions.

A typical snow cave can provide meaningful shelter for two to three people, but larger shelters are possible, though you’ll have to pay close attention to the strength of the roof to make them work.

If you have other capable members in your group, an excellent strategy is to rotate workers so that each member has a chance to regulate their temperature before they start getting too sweaty and soaking their clothes.

Snow Cave Risks and Dangers

Snow caves are one of the best survival shelters in cold settings, and are more than capable of housing you and other members of your group for several nights of rest with very little work needed after the initial investment.

However, you must use caution, as compared to other forms of improvised shelter, snow caves do come with several attendant risks.

Most of these risks can be avoided or mitigated through the use of best practices and paying careful attention during the construction phase.

Working sloppily or in a frenzied rush to provide shelter from truly terrible conditions only increases the likelihood that you will fall prey to these hazards, so take care!

Hypothermia / Frostbite

Hypothermia and frostbite are serious concerns whenever you are building or occupying a snow cave.

You might think this is a seriously “duh” sort of problem when your shelter is itself made of snow, but the issue is somewhat more nuanced.

As mentioned above, excavating a snow cave should be done with tools, even improvised tools, if at all possible.

Keeping your hands in direct contact with the snow (even if they are gloved) will chill them rapidly and it will not take long before frostbite begins to set in.

It can be harder to notice than you think, too, especially in your extremities and damage can begin to accumulate before you can correct it.

Also as effective as snow caves are at blocking out wind and insulating you against the cold, they will still be plenty chilly enough inside, meaning you’ll need to keep your winter clothing on or even make use of a fire or other warming solution.

Just because you have excavated a snow cave does not mean you can strip down to your jammies and relax!

Self-Inflicted Injury

As mentioned above, exclamation of the snow cave is best done with tools and is hard work.

Working hard with sharp tools when you are already numb from cold or exhausted is a great way to deliver a self-inflicted injury. Particularly when working with picks or ice axes extreme care must be used.

Even if you are doing something mundane like shoveling snow or using buckets to haul it away from the entrance tunnel, remember the correct principles of physical labor.

Snow is heavy and careless lifting or twisting can see you pull a muscle or worse.

Also, you must always be cautious when working on a slope so that you do not have a slip that results in a tumble down a hillside.

You are almost at the finish line when constructing your snow cave, so make sure you work smart and avoid injury.

CO Buildup

Carbon monoxide build-up can be a major hazard inside the close confines of a snow cave if it is not properly vented.

The typical perpetrator is a camp stove but some folks even make use of a small fire to help warm the interior of the snow cave.

The uninitiated might think that the open entry tunnel is more than enough to ensure plenty of fresh, moving air is making it to the interior, but this is not always so, and furthermore snowy conditions or small avalanches can cover or block this tunnel.

If you leave a fire burning and your entrance tunnel becomes sealed the small inner volume of your snow cave will quickly accumulate deadly carbon monoxide, a particular risk when you are asleep.

Most sleeping victims of carbon monoxide poisoning never wake up, so you should always ensure you install emergency ventilation/air holes in your snow cave either where the walls meet the roof or in the roof itself.

Cave-In / Collapse

One of the scariest and regrettably most common mishaps that survivors endure when using a snow cave is a collapse of the structure itself.

This usually results from improper design, a flaw in compacting the snow, or exterior accumulation of weight on the roof, either from excessive snowfall, or something like an avalanche, falling tree, branches, or from someone walking over it.

When this happens, the heavy, slushy snow can possibly pin you in place, trapping you or suffocating you.

At best, you’ll be rendered shivering cold, possibly wet, and without shelter, necessitating you act fast to arrest the situation.

Always make sure you pay close attention to detail when constructing your snow cave, making sure that all elements are done to the best of your ability with correct proportions and preparation.

If there is any chance that other people could be moving through the area, take the time to line the exterior perimeter of your snow cave with markers, even if they are just tall sticks jammed into the ground.

This will prevent the unknowing from treading over the roof of your perfectly camouflaged snow cave.

Asphyxiation

There is another breathing hazard associated with snow caves that is even more insidious than carbon monoxide build-up resulting from combustion in or near the cave.

As temperatures slightly rise inside the snow cave, be it from body heat or some other heat source, along with humidity from the breathing of the occupants the inner surfaces of the snow that make up the cave have a tendency to ice over.

This thin crust of ice further reduces the amount of air that makes its way into the cave, air that would normally move through the snow itself.

This can result in low oxygen levels and is particularly dangerous when the entrance tunnel and ventilation holes are blocked by fresh snowfall.

Considering that this is a hazard whether or not you are burning anything in or near the cave, what is a survivor to do?

You have a couple of options. One is to put people on the watch to constantly maintain the entrance to the cave and any other ventilation holes in order to assure the influx of fresh air.

Another option that is sometimes employed is poking a walking stick, ski pole, or ski itself through the roof or wall of the snow cave so that you always have an emergency opening you are ready to make use of.

All you need to do is carefully remove the obstruction and you should have a hole leading clear to the outside air.

Conclusion

Snow caves are one of the oldest and best cold weather survival shelters, and are used all over the world by man and animal alike wherever large quantities of snow accumulate on the ground.

Snow caves provide fantastic insulation and protection from wind, and they are a simple design that requires no additional material for construction, making them one that all preppers should know by heart.

Snow caves do have some attendant risks with use, but most of these are easily mitigated, especially in a group situation.

Take some time to practice excavating and living in a snow cave the next time you are heading out into a white, snowy wonderland.