The rule of threes is famous in survival circles — I’ve written about it before — but now I want to narrow in on what is usually the top priority. You can go three minutes without air, three hours without shelter, three days without water, and three weeks without food. Talking about air would be silly, so this article is about shelter.

I’m not going to teach you how to build a shelter in this lesson. Instead, I’m going to talk about what qualifies as a shelter.

Really, Three Hours?

What does it mean when someone says you can go for three hours without shelter? I mean, you die if you don’t get water for three days. You die if you don’t get air for three minutes. You die if you don’t get food for three weeks. I suspect most of the people reading this have gone more than three hours without shelter on multiple occasions in their life. Maybe you went to the beach and hung out for a bunch of hours; perhaps you took a long walk, there are many other ways you might have been out in the elements for more than three hours in your life.

The thing is, all the rules are flexible. In harsh conditions, three hours is a reasonable length of time that it might take for you to die without shelter. This isn’t a countdown situation; it’s more of a way of setting your priorities. Shelter should be the first priority if you can breathe.

Okay, so What is Shelter?

That sounds like a stupid question, but it isn’t. Shelter doesn’t necessarily mean a structure you built. There are a lot of things that qualify and the amount of labour, as well as the amount of protection, varies greatly.

The environment you are in will also dictate what kind of shelter you require. A perfectly reasonable shelter in Papua New Guinea doesn’t even qualify as shelter in the arctic circle.

Basically, you need to be able to block the environment from affecting you. In high wind, a wind block counts. You are sheltered if you have a large rock in the windward direction. In heavy rain, you need something with a waterproof roof. In harsh sun some palm leaves might do the job. In cold weather, you need something that provides insulation.

Some Examples

If you are on a sun-drenched island in the South Pacific, you will need to find shade quickly. It might seem like no big deal, but the sunburn you can get from a place like that can be catastrophic. Hell, it can kill you. So, grab yourself some palm leaves and hide under them. Maybe weave them together, so they form more of a roof. As much as you need out of the sun, the rain, when it hits, will take your breath away. That’s surviving on easy mode by the way.

If you are in a temperate forest, you can look for a rock face and then lean a bunch of pine boughs against it. If the pine boughs are close enough and tight enough, they will block a lot of weather. They can even keep out some of the rain.

Cold is the worst enemy when it comes to shelter. Cold and wet as a combo are deadly. If your environment is cold, then you will need to build something much better insulated. Keeping the interior of your shelter dry is also essential.

Caves

Caves are a no-brainer, right? Well, yeah, but… the thing about caves is that they are such a natural shelter that a lot of animals agree. You don’t want to argue with a bear over who has the rights to the cave. I’ll give you a hint; it isn’t you.

If you see a cave and it looks promising, there are a vast number of things you will need to consider. First, prior occupancy: look for signs of the aforementioned bear or any other large animal that is using the place already.

Then there is the chance of cave-ins. The cave might not be stable. You will want to make good and certain that it’s reliable.

Getting lost is another issue. If you go out of sight of the entrance to the cave, you run the risk of getting turned around. Some cave systems can be hundreds of kilometres of twists and turns. You might find yourself lost forever — not a great outcome.

Floods are a thing in caves too (that’s going to come up again in other sections). If your cave floods from time to time, well, you might not want to be there when it does.

If you are in sight of the entrance, you are probably not going to have significant issues with gas buildup, but it’s not impossible. If it does happen, you can find yourself drifting off to sleep due to oxygen deprivation (remember the first rule?), and that’s that.

Caves become a pretty last resort sort of shelter because of all these factors. So, despite the convenience much less of a no brainer than they seem at first.

What to Build

For cold, space is your enemy. A small shelter that’s decently insulated will be able to keep you warm far more easily than a large shelter, even with the same level of insulation. Your body heat will warm the air around you, slowing heat loss a great deal. A lean-to that is barely larger than you might be your best option. Make sure you are not directly on the ground, though. A wiki-up or wigwam is often a good choice. Something like a log cabin might seem tempting, but they are a lot of work and only make sense if you are going to be in the bush for a very long time (months or years).

Ground

The ground is a great heat conductor. It will leach the heat out of your body incredibly fast. Make sure you put something under you. A bed of moss, pine boughs, piles of leaves, some sort of insulator. If you can do a bed of boughs then insulation that’s even better. That way you are off the ground and might also be far enough off the ground that you avoid water should it get into your shelter.

Depressions/Basins

It might seem like a ravine or trench is a good option. It has two walls; you can probably put up a makeshift roof pretty quickly. Add a wall, and you have yourself protected pretty well. A lot of trenches are formed by rapidly moving water. Maybe the dry riverbed has been dry for hundreds of years. Perhaps it fills with water every time there is rain. Flash floods happen, and they are terrifying.

Higher Ground

Yeah, you almost always want to be on higher ground. Not right on a ridgeline, since that will leave you too exposed to the wind, but higher up if possible. Being close to a water source like a lake or river might bring you down further. Even then, not right on the bank. Flooding is a problem.

So, a Quick Recap

Use your environment as much as possible in your shelter

Avoid caves

Avoid trenches

Don’t go places that might flood

Space is your enemy

Environment dictates needs

That’s the basics. The rest is details, and details mean the difference between life and death if you are caught outside. I will be doing much more on shelter building and shelters in the near future (including a review of the emergency shelter I bought from the dollar store).

Until then, stay warm and dry.