Disaster! You’re lost in the mountains,
gone astray in the jungle or stranded in the desert! How do you survive?
Surely you must have a mental checklist of survival strategies
from all those movies and tv shows you’ve watched!
But which survival tips will save your life and which will more likely get you killed?
Let’s find out.
I’m Stu, and welcome to Debunked,
where we sort the truths from the myths and the facts from the misconceptions.
Like, Subscribe and let us know in the comments about
a survival myth you were told that turned out to be less than useful.
Should You Light A Fire In A Cave?
You’re lost in the mountains, and the sun is going down.
Protection from the elements is obviously going to be advantageous to survival,
and – like many an intrepid explorer in films, and on TV – you happen upon a cave.
You establish it’s free of any other residents, bears and what not,
but it is pretty cold.
Like all good survivalists, you’re carrying a flint and steel,
so you gather the driest-looking materials you can find around the mouth of the cave.
But is it safe to light a campfire in your temporary residence?
Smoke inhalation can be deadly,
so the last thing you want in the confines of your cavern is a dangerous build-up.
It might feel like the mouth of the cave would be the best place to light your fire –
– so the smoke can escape through the entrance.
But according to an article published in the scientific journal Nature,
which used modeling and real-life experiments to investigate Neanderthal cave fires,
this may actually be the worst position in terms of smoke dispersal.
The study found that…
…a large amount of the smoke ended up back in the cave, building up to unsafe levels.
They also found that when the fire was placed at the back of the cave,
the pattern of airflow meant that the smoke actually dispersed more favorably,
rising up the back wall and, via the ceiling, leaving through the mouth of the cave .
Even so, the part of the cave containing the fire – which is obviously the warmest
part – had smoke levels that were extremely unsafe for medium- to long-duration exposure.
Interestingly, the study also noted that Neanderthal fire hearths were
most likely to be situated in the middle of the cave.
The authors concluded that they used this placement as a sort of compromise – enabling
some degree of smoke dispersal but also allowing room for communal gathering around the fire.
On top of the smoke problem, if the ceiling of your cave is low, the heat from a fire may
cause the rock above to expand, potentially resulting in a deadly ceiling collapse.
In short – you should probably avoid lighting a fire in a cave wherever possible.
Though Neanderthals certainly did it, it’s likely that their significant
experiential knowledge enabled them to do this much more safely than you or I could.
If there happen to be plants growing in the vicinity, a safer option would be to use the
vegetation to cover the floor — and your body — providing much needed insulation.
Does Alcohol Warm You Up?
On the subject of insulation,
some of you might be familiar with the term ‘beer jacket’ or ‘beer coat’,
– the idea that a dose of booze can protect you from the effects of the cold.
So should you whip out the hip flask and turn to
the tipple as night falls and temperatures plummet?
Though those of you of drinking age may be adamant that you’ve actually experienced it,
I’m afraid it’s our duty to deliver a double shot of bad news
– not only is the idea that the hard stuff can protect you from the cold a myth, but,
depending on your circumstances, it could actually be very dangerous.
The reason you might feel warm after consuming a
boozy beverage is that alcohol itself acts as a vasodilator,
meaning it causes blood vessels to widen.
When the blood vessels near the surface of your skin dilate,
the increased blood-flow is registered by the densely distributed sensory receptors
as a sensation of warmth.
Crucially, though,
your body temperature isn’t actually rising.
Instead, the heat energy generated by your metabolism is being redistributed – away
from your core, which houses your vital organs,
towards the surface of your skin, where it’s lost to your surroundings.
This can lead to a lowering of your core temperature and, ultimately,
if you’re exposed to cold temperatures for long enough, hypothermia, which can be fatal.
In addition, the sensation of being warm that’s triggered by vasodilation could cause sweating,
which would further accelerate your heat loss,
and inhibit shivering, the purpose of which is to warm you up.
Last but not least, lapping up liquor impairs your brain function – delayed reaction times,
altered perception and reduced coordination
all increase the chances that you’ll have some
sort of accident – the last thing we want in our mountain environment.
So put the hip flask down, and try to get some sleep.
Does Boiling Water Make It Safe To Drink?
Having wisely binned off the booze, you make it through the night.
You wake with a raging thirst – along with shelter,
hydration is right there at the top of the list of survival musts.
Venturing out once more, you find a rather dubious looking pool of water near your cave, which,
along with an unusual colour, boasts a distinctly off-putting aroma. Still, water is water, right?
Boil it, and we’re good to go!
Well, the boiling point of water – 100°C (or 212°F) –
certainly is hot enough to kill most bacteria, viruses, and parasites almost instantly,
and a good rule of thumb is to aim for a vigorous rolling boil for a full minute.
At higher altitudes, the decrease in atmospheric pressure results
in a lowering of water’s boiling point.
The CDC advises that at altitudes of over 2km (6,500 feet),
you should keep a rolling boil going for a little longer.
Though this extended boil won’t raise the temperature of the water any higher (that
would defy physics!), the kill time of certain pathogens may be
longer at lower boiling temperatures – three minutes should do the trick.
Unfortunately, though, not all boiled water is safe to drink.
Should the land you’re on have a history of agricultural or industrial use – a nearby farm,
or a mine, for example – toxic chemical and/or heavy metal
contaminants may accumulate in pools of standing water.
Boiling the water won’t remove these contaminants.
Algal toxins from cyanobacteria, commonly known as blue-green algae,
are also not neutralized by boiling.
Ingesting these toxins may lead to gastroenteritis – causing vomiting,
diarrhea, fever and headaches – and may even affect liver and nervous
system functioning. None of these things are going to help you survive in the wilderness.
Helpfully, several US government websites host guidelines to help you tell the difference between
simple aquatic weeds and harmful algal blooms – we’ve put some links in the description below.
On balance, if your pool of water can be passed over in favor of running water,
it’s probably a safer bet to boil and drink that instead.
Although cyanobacteria are present in running water,
harmful algal blooms are much less likely to occur in rivers and streams.
Can You Drink Water From A Cactus?
Let’s raise the stakes in our hydration challenge, and take ourselves off to somewhere even more
hostile to survival: the desert – a formidable foe for even the most seasoned survival expert.
No shelter from the blazing sun, a dangerous lack of navigational cues,
and, almost by definition, little to no water.
It’s understandable then, that the sight of a fat green cactus might lift the
spirits of a dehydrated, waterless wanderer. Cacti, like all plants,
need water to survive. Surely this spiny desert dweller is a guaranteed thirst-quencher?
Unfortunately, it’s not that simple.
First of all, cacti don’t contain reservoirs of free-flowing water.
Instead, they have dense,
spongy flesh that stubbornly withholds whatever moisture the plant contains.
And it gets worse: should you manage to squeeze a few drops from the tissue, it may do more harm
than good. The water inside many cacti species is highly acidic and contains toxic alkaloids.
It’s for this reason that the name given to the Coville barrel cactus
by the Seri people of the Mexican state of Sonora is ‘the barrel that kills’.
Consumption of its flesh and/or juices is reported to cause nausea, diarrhea, and even
temporary paralysis, all of which represent obvious barriers to survival in the desert.
It’s likely that this widespread but dangerous survival strategy reached the public imagination
via the 1948 Western The Three Godfathers, starring John Wayne,
JW “The only water we’re gonna get is right over here…”
“Barrel head.” “It ain’t the best water and it’ll take time”
‘The Duke’ and his traveling companion chop up a barrel
cactus in search of water. Thanks for nothing, JW.
At a pinch, you may be able to find some water in rock crevices,
where changes in temperature overnight may cause condensation and pooling to occur.
Pockets of more lush-looking vegetation, and animal tracks,
might also point to the presence of water,
though desert-dwelling animals are generally able to survive
for longer periods without water and may travel long distances to find it.
Really, the best advice here is to never,
ever head out into the desert without adequate quantities of water,
and to make sure you travel with somebody who has plenty of experience and local knowledge.
We’ve done the mountains, and we’ve done the desert. Let’s cap things off with a
hazard that’s exclusive to environments with plenty of fresh, natural water.
Should You Burn, Salt Or Rip Leeches Off?
The rainforest. Lush, green and humid. Here, moisture is so abundant
that creatures that need to stay wet to survive can get by in the long grass.
Creatures like leeches, for example. Everybody’s favorite wriggling,
glistening, bloodsuckers can be found in and around freshwater the world over,
and in the world’s rainforests they are particularly prevalent
and can be horrifically oversized – the Giant
Amazon Leech can grow to 45 cm (almost 18 inches) in length.
Perhaps thanks to an iconic photo from 1971,
depicting a US soldier in Vietnam using a lit cigarette to burn leeches from his forearm,
many of us have been left with the impression that this is the best way to remove them.
What’s that?” “It’s to burn off the leeches.”
While burning a leech obviously will kill it,
it may have some unintended, and downright unsafe, consequences.
Like all animals – including us – the digestive tract of a leech contains a multitude of bacteria.
Burning a leech that is attached to your skin could cause it to regurgitate some
of the contents of its stomach into the wound it’s made on your body,
and these microbial invaders could go on to cause an infection.
Can you pour salt on them to get them off?
No – the same problem applies.
So, how should you remove a leech? According to Anna Phillips,
a curator and leech expert at the Smithsonian,
“A leech holds onto its host with suckers at
each end – breaking the seal is enough to pull them off.”
Gently slide a flat object – a fingernail or credit card,
for example, under the edge of the sucker, and it should let go.
It’s important not to pull or rip the leech off however as its suckers
or teeth may be left behind in the wound, again leading to infection.
Alternatively, as unappealing as it may sound, you could just let the leech do its thing,
they stay attached for 30-60 minutes after which they simply drop off.
While we’ve shed light on some pretty dangerous survival myths here,
if you want to stay safe, avoid dangerous destinations and situations!
But, if you’re determined to venture out into the wilderness,
it’s worth remembering some simple precautions:
Travel with people who know the terrain – there’s no substitute for first-hand experience
Educate yourself on your destination – every destination has its own unique challenges.
Don’t go too big too soon - start with smaller trips and build up to bigger ones.
Let somebody know where you’re going – whether it’s a trip to the woods
or base camp at Everest, make sure trusted people
know where you’re headed and when you expect to be back.
Stay safe, and thanks for watching!