Killer Cold Deadly Pole to Pole

My name's Steve Backshall.

And this is Deadly Pole To Pole.

Ohhh!

From the top of the world to the bottom.

Whoa!

Deadly places...

deadly adventures...

and deadly animals.

And you're coming with me, every step of the way!

Arghhhh!

My crew and I have been to some pretty extreme places

on our travels.

I think we've got a bit too many sharks!

That is phenomenal!

But there's one environment that's deadlier than all the rest.

It is Extreme cold.

I'm not talking about your average winter day,

but full-on, bone chilling, lethal cold...

with the power to shut down our bodies...

I'm not putting this on, I swear.

..and even stop our very cells from functioning.

It has more killer potential than any predator.

Argh, let me out.

To find out more, I've come to the Extreme Environments Laboratory

at the University of Portsmouth.

Here, I'm going to be shut in a room that's colder than your freezer

and put in chilly water until my body starts to shut down,

which is just the most ridiculous way to spend a morning.

Whether in the frozen north or the barren ice fields of Antarctica,

life in the world's freezers

has found some ingenious ways of fighting off the cold.

I want to explore the challenges they face,

to learn what it takes to stay alive.

First up, it's time for a dip.

Inside this tank is water that's been chilled

to 12 degrees centigrade and that is very cold.

If I was on an expedition

and I fell into water like this it would instantly become

a survival situation and to find out how and why, I'm going to be

dumped in here until it brings me

right down to hypothermic.

While I get my trunks on, my crew prepare me

a nice cold bath.

I've never been, kind of surrounded by quite

so many different machines that go ping.

Which is all a little bit nerve-racking.

Taking a plunge in chilly water can be risky business.

It has to be done under strictly supervised conditions.

This is something you definitely shouldn't try at home.

Cold water can suck life-giving heat away from our bodies much quicker

than air.

Chuck in icebergs and crashing waves, and a quick swim

soon becomes a deadly dip.

But there's actually one group of mammals that spend their whole lives

in these conditions. I want to see how I shape up to them.

So there are a number of things here that are monitoring my progress.

I've got these pads which are monitoring my heart activity.

I'm also wearing an internal thermometer so you'll be able

to actually see what my core temperature is.

If that starts to drop then I'm in real trouble,

even a drop of one or two degrees could be very dangerous.

-OK.

-Three, two, one. Here we go.

Oooh.

Oh, wow.

It's colder than I was expecting actually.

In a real immersion situation this would be the most dangerous bit,

because your body is instantly, has a shock response to the water.

So the first thing that you want to do is to breathe in

very, very deeply.

You can imagine if you were going into the sea,

and there were waves and ripples, it would be very, very easy

to swallow a lot of water in one go.

And if that happened, that would probably be the end of you.

Oh, oh, that's actually that is colder than

I expected, I'm already getting brain freeze and I can feel

my fingertips starting to go a little bit numb already.

Less than a minute! That's not a good sign.

My body's already starting to shake and shiver

and generating a bit of extra warmth, just try and warm me up

from the inside out.

I really don't want to be in here for 40 minutes,

it's just horrible already.

Something that's happened straightaway is that all

of my hairs on my arms and body have stood up, erect and they're trapping

a layer of bubbles. Those bubbles

contain air and they can be heated up by the temperature of the body

to provide an extra layer of warmth.

In a human being, because we're not very hairy it doesn't work

very well, but in a lot of marine mammals, animals that spend

a lot of time in the water, they have incredibly dense hairs.

And the densest of all furs belongs to the silky sea otter.

These bundles of fluff may look cute...

but don't be fooled.

Their pristine pelts are perfect

at repelling the perils of chilly water.

Essential if you want to hunt in icy seas.

To find out why they need this hardcore insulation,

I've headed to Alaska. Wow.

There's a pretty good raft just over there.

Oh my goodness that's unreal, wow.

This is one of the best places on the planet to get up close

with these mighty mustelids.

They're just wonderful animals aren't they,

like little floating bears.

But there's only one way to really understand

the struggles they face.

I can't quite believe I'm saying this,

but I'm going to need to get in and it looks really, really cold.

The water is around a teeth-chattering 10 degrees C.

That's even colder than the lab.

Oh.

Crumbs. It really quite takes the breath away. It's very, very cold.

Of course the sea otter has such thick, dense fur,

the densest fur of any animal that it can actually live in these

waters with no problems whatsoever.

Even with my wet suit though, this is a bit unpleasant.

OK, I'm going to dive down, have a look.

Within seconds I'm overcome by the cold.

I can't believe they manage to live in this, day in day out,

let alone scour the sea bed for tasty clams.

It's an utterly alien world, and after just minutes,

I'm ready to come out.

Argh, my head.

Oh, I've got the worst ice cream headache I've ever had.

Phwoar, it's so cold. Oh.

The sea otter, a hardy hunter, with a world-beating wet suit.

Back in the lab, without the benefit of insulation,

my core body temperature is starting to plummet.

We're beginning to see this on our thermal imaging camera,

which shows the heat of my body.

Yellow and white areas are warm, while cold looks dark blue

We human beings just are not built for this.

Perhaps the reason that this is such a challenging environment is

that water conducts heat away from the body more than 20 times

more efficiently than air does, so you cool down

faster than you would do in air, being in water like this.

It becomes very uncomfortable, very quickly indeed.

I've been in for seven minutes now and already I'm shivering

quite a lot. The thermal imaging camera though shows that

my head and face is still exactly the same as when I got in here

but my hand, if I put that onto my face,

you can see how that cooling works. Look at that.

I look a bit like a clown it's kind of a bit strange.

But you can see where the surface of the skin has cooled.

In that case, not very much, so instead of being white or yellow,

it's gone orange or red.

But in my hand, completely black.

Now this is one of the most important...

I've just rubbed the end of my nose, it's gone blue!

That is brilliant.

That looks very, very strange indeed.

We human beings, as mammals are, as you can see already,

very, very poorly adapted to life in these kind of conditions.

But we have some quite close relatives

that under the skin are not too dissimilar to us,

that deal incredibly well with temperatures like this.

They have to deal with cold water every single day of their lives.

And where better to find them than in the icy waters

of the high arctic?

Yes!

There are splashes, waves,

eruptions of white water,

no more than about 30 metres off in front of us.

Every once in the while, a white head breaks the surface.

Every summer these waters are inundated

with hundreds of curious creatures.

Meet the beluga, the hardy white whale of the frozen north.

There are very few marine mammals that could survive

an entire lifetime in the Arctic Ocean.

The way they manage this is through a thick layer of fat

underneath their skin called blubber.

This blubber allows the belugas to survive in waters

that can drop to nearly minus two degrees C.

It's a special kind of fat that can grow as much

as ten-centimetres thick and make up half of their body weight.

It's an incredibly efficient insulator,

especially when the beluga is diving deep in arctic waters.

Many marine mammals rely on blubber to keep them warm

both topside and under the waves.

Some of the blubberiest blubber is worn by the elephant seal

of the southern ocean.

Which can weigh more than a family car,

keeping it warm in the worst weather.

'Never mind a whole lifetime spent in winter water

'my body's shutting down and I'm shaking like a leaf.'

I'm not putting this on, I swear.

This is really my shivering is going.

Um, I don't feel as cold as I did before, though.

But already, when I think about it,

my brain's not working as well.

Already now just...

just speaking and trying to think about simple things is quite hard.

'I may be losing my marbles

'but things are about to get a whole lot worse.'

At the moment there is still one part of my body that is warm -

my face and my head because it hasn't gone under.

Really, I suppose, I ought to go the whole hog.

So let's just see what happens if I put my face in.

OK, so now on the thermal imaging camera you can see already

that my eye sockets are still very warm,

I guess, because I had my eyes tight closed,

but you can see all of the heat already leaching away

from the skin on my face.

The only way us humans really stand a chance of surviving cold water

is to learn from the adaptations of marine mammals.

Kitting ourselves up head-to-toe in hi tech insulation.

But even then we can't match our aquatic cousins

and are only able to stay in the coldest waters for mere minutes,

before we have to come back to our own world.

Without any of this protection, my time's nearly up.

My body core temperature hasn't quite dropped by one degree C,

but I think we're going to call it a day there

and lift me out and see quite how extreme the effects have been.

OK, Mike, take it away.

You can see that...my...skin

that was out in the air is still...yellow,

which means it's not far off its normal temperature.

But the rest of me is pretty much the same temperature as the water.

So it's blue, my skin's dark blue, except under here in my armpits,

where my skin's been clasped together and it's kind of

insulated itself.

But I'm just so glad to be out of there!

'It's phenomenal how debilitating the cold can be for us humans.'

Right, so if you could just hold that.

No spinning, just twist that as fast as you can.

'Unlike our marine mammal cousins,

'even just a short dip can make the simplest tasks nearly impossible.

'I can't feel a thing.'

OK, fingers if you can, rather than twisting.

'This is a real challenge.

'Right, test done and it's time to warm up. I can't wait!'

-Agh, argh!

-Careful.

Ahh, that's so nice!

-Oh!

-So you can bend your knees, keep your feet under, there you go.

Ah!

-It's good, isn't it?

-It's just amazing!

That's probably the best bath I've ever had.

'But I'm not done yet.'

BATH TOY SQUEAKS

Marine mammals certainly seem to have the ice cracked,

but they're not the only subzero survivors on the block.

Life on the land is just as tough.

At the poles, temperatures can plummet to minus 93 degrees C.

With some of the worst weather on the planet,

you have a supremely savage scenario.

Animals that live here use awesome adaptations to stay alive.

To learn more about how they live life in the freezer,

there's only one thing for it - I'm going to have to get in one.

Right, we're now in a sealed room

at about minus 18 degrees centigrade, which is

about the same as the inside of your freezer at home.

It's also the kind of entry level for extreme Arctic temperatures.

At this temperature,

most Arctic animals wouldn't even start shivering.

And, for me, in all these clothes, it's actually pretty bearable.

I could manage to survive here for quite a while.

The big game changer, though, is if you get wind,

and we can recreate that with this fan.

Johnny, do you want to switch it on?

FAN BLASTS

So, this is now getting going,

and it's blowing wind at about 10mph.

At 10mph, minus 17 or minus 18 degrees C

feels like minus 30 degrees C.

For us human beings, at minus 30,

exposed flesh will start to freeze almost immediately,

so we have to protect ourselves.

And we do it with an external hard-shell jacket

made of special man-made fibres.

Animals do it in a totally different way

by having very thick, dense, external guard hairs -

animals like the musk oxen.

Weighing over 300 kilos,

these musk oxen are built like fluffy tanks,

with huge shoulders, strong, muscular legs,

and a thick coat that can protect them from the worst Arctic storms.

It contains some of the longest hairs in the animal kingdom.

They are true cold weather champions.

In Somerset Island, I managed to get my hands

on the secret of their success.

So, as human beings, if we want to survive

in an Arctic winter, then we need to use layers.

On the bottom, we'll go for a nice, warm fleece, and on top of that,

something like a Gore-Tex jacket, which cuts out the wind.

The musk oxen has something which is far more efficient.

This is one of their pelts.

So, on the outside, you have these thick, dense hairs,

which cut out the wind.

Underneath it all, you have this wonderful, soft underfur.

It's almost like cotton wool, and that'll trap air close to the skin.

This is far more efficient than anything that modern technology's

managed to come up with. In fact, if I was to try and keep this on

for just a couple of minutes, I would overheat.

This is the secret to surviving in extreme cold.

To show how vital all of these layers are,

we have a thermal imaging camera over here.

Once I start to take all this stuff off, you'll see a real change.

So let's get rid of my windproof layer.

It's already getting quite icy, look. Look at that! Hmm.

Oh, crunchy.

OK. Now we're getting down to proper insulation layers.

What I've got here is a down jacket.

The inside of this is filled with feathers, with down, like this.

So, even today, in our hi tech era,

we still use proper, real goose or duck down feathers

as insulation inside this.

There is nothing that human beings have managed to create

that can have the same insulating properties as these feathers.

Ducks and geese may use these insulating waterproof feathers

to soar high above frozen landscapes

and dive deep in icy Arctic waters...

..but this is Deadly, and we're on the prowl for predators.

The elegant great grey owl is one of the most well-insulated birds

on the planet.

It uses a down jacket to help it hunt in frozen forests,

watching and listening for voles under the snow.

Its feathers also allow it to pounce in stealth mode,

helping it fly quietly into the kill.

Unfortunately, for the purpose of this experiment,

I'm not allowed the luxury of thermal feathers.

OK, so, now, I'm going to lose my main insulating layer

and this is when the thermal imaging camera

is really going to start to see the difference.

Ohhh, look at that! Already, yeah, I can see

bright, bright orange, and as my hat comes off, look at that -

it's almost white, my head!

But the temperature we're at at the moment, minus 18,

I really don't want to be like this for very long.

Now I'm down to the base layer. This is incredibly important.

It doesn't have to be very thick, but it's very tight to the skin,

and it's incredibly important to insulating a thin layer of air

very, very close to the skin.

You'll find this in all Arctic animals,

especially things like bears and foxes.

To live in a place where seasons look like this,

you need decent thermals.

And a polar bear has some of the best

thermal pants on the planet.

Just like the musk ox, it uses guard hairs to keep out

wind and snow.

But its insulating underfur is so good,

it allows it to stay warm on land and at sea.

But it doesn't just survive here, it thrives,

using its thermals to help it hunt on the ice.

Its neighbour, the Arctic fox, has even denser fur.

It can withstand the harshest winter storms

without the need for shelter,

even sleeping out on the ice,

using the thick thermal fur of its tail like a sleeping bag.

OK, and last of all, right down to bare skin.

Now, obviously, there are no land-living,

Arctic mammals that would do this.

You can see, for me... I mean, I am white hot. All that energy

is just instantly being lost through my skin. Perhaps as much as

90% of my body heat is just going to go instantly, straightaway,

from my skin. And if the wind was blowing,

I would be in very, very big trouble within a matter of minutes.

And I have to say, already,

I'm desperate to get my clothing back on.

There is, however, one last thing that Arctic animals can do

to make sure they're insulated,

and that is eating like you would not believe.

Our old friend, the Arctic fox,

takes advantage of warmer months to lay down

as much as half its body weight as fat

in preparation for the cold.

When the winter comes, it's not only got good insulation,

but calories to burn,

to fuel the fire to keep warm and stay alive.

ARCTIC FOX BARKS

Unfortunately, I'm nowhere near as good at piling on the pounds.

It's time for me to leave.

Argh, let me out!

It's pretty obvious that when it comes to surviving extreme cold,

us humans are rubbish compared to the birds and mammals

of colder climes.

Without the insulation of blubber and fat,

or the protection of feathers and fur,

we just don't stand a chance.

But there's one last cold weather strategy

that trumps all these tricks, and it has to be seen to be believed.

This is a surprisingly wonderful find.

It's a woolly bear caterpillar.

This is one of nature's great survivors.

These caterpillars live in the frozen north

and have to make it through harsh Arctic winters.

The way they do this is by completely

shutting down their bodies and freezing themselves solid.

But when the summer comes, these hungry caterpillars

rise from the dead, and are able to munch on

the freshest Arctic veg.

A caterpillar that can become an ice pop may sound impressive,

but it's a pretty simple animal.

There's a far more complex critter that can pull off this trick,

and it's my supreme ice-cold survivor.

The wood frog lives in North America,

where the winters are harsh.

Its range may even stretch up into Alaska, further north

than any other frog.

Cold-blooded creatures struggle to survive in cold weather,

so this frog takes extreme survival to another level.

When the winter temperatures start to drop,

the wood frog takes refuge underground.

As it gets colder still, the icy frost penetrates the soil.

Being cold-blooded, our freaky frog starts to freeze.

All living things contain water in their cells.

As this water freezes,

it forms spiky ice which can rip these cells apart.

But the frog uses clever chemistry to protect itself.

It packs its cells with sugars,

which force the ice to form in places where it can't do any harm.

With no breathing, no movement, and even no heartbeat,

the frog should be dead.

But the sugars stored in its body provide just enough

energy to keep the cells alive through the deepest parts of winter.

Frozen in time,

this incredible frog can survive for weeks on end.

But even with all its vital functions on hold,

it hasn't croaked it - there's life in the old frog yet.

When spring arrives and the temperatures start to rise,

the frog's body begins to thaw.

The defrosted heart muscles kick-start it back into action

and blood starts pumping around the body.

The once-frozen frog is almost completely back to normal

within just 24 hours.

And it hops to it, taking advantage of being the only frog in town,

free to gobble up insects ahead of the competition.

This Frankenstein frog has to be the ultimate subzero survivor.

Instead of fighting off the cold with blubber and fur,

it embraces it, almost making itself dead in the process.

Any environment that forces an animal to go to lengths like that

has got to be deadly.

Join me next time for more Deadly Pole to Pole.