Episode 8 Richard Hammond's Miracles of Nature

'Animals are amazing.'

That's astonishing.

'And the more we find out about them, the more amazing they seem.'

That feels pretty harsh.

'That's why scientists all over the world are trying their best

'to copy them.'

This is in the future.

'Making brand new inventions...' Tomato juice.

'..based on what animals can do.

'Some are astounding...'

We've just dived under the sea.

'..some bizarre....'

This is not at all pleasant.

Yes, it's gone!

'..but they're all inspired by the miracles of nature.

'Episode 8.

'How a husky can help us... keep our cool.

'In searing conditions like these,

'there comes a point when the human body can actually stop sweating.

'Which is a worry.

'Because if you can't sweat,

'you lose the ability to regulate your own temperature.

'And going more than just a few degrees above normal

'will start to affect your brain.

'Until you lose the power

'to do even the simplest of things.'

As I shall now demonstrate using this child's toy.

Obviously, for this to be rigorously scientific,

I should first have demonstrated to you

how good I am in my front room at room temperature.

I'm brilliant at it, that's all you need to know.

I'll now try it on a blazing hot salt pan.

Right, here we go.

-TOY:

-Bop it!

'The idea is that I just copy what the toy tells me to do.'

Twist it!

Twist it!

'But I seem incapable

'of following more than three or four instructions.'

'Which even by my standards is bad.'

What actually is happening is as your brain gets hot,

it lets you down in three critical areas.

First of all...

I've forgotten!

What actually happens, as your brain gets hot,

it lets you down in three critical areas.

First of all, working memory.

That's, in this case, remembering which of these things does what.

Then your short-term memory,

remembering what the machine's told you to do.

And finally, co-ordination.

You might remember what it's told you to do and which one does it,

but you've got to get your hand there and use it.

Which is why, ridiculous though it might look, for our purposes,

this was actually quite a good test of those three things at speed.

Do some more.

Twist it!

No!

Stupid toy, anyway.

'Luckily, the natural world has a way to keep our brains cool.'

It's just that it's not found in the desert.

It's in the frozen north.

An animal that can survive

some of the coldest temperatures on the planet.

That animal is the husky.

Huskies have evolved to live in unimaginably cold conditions.

And not just to work and play, also to sleep on the ice

at minus whatever, and they do that, cos, yeah, they have a fur coat,

but it's not just a single fur coat, they're wearing two.

There's the outer layer of coarse, waterproof hairs,

and on the inside, underneath,

there's a second layer of this soft, insulating fur.

And it works really, really well.

The problem is, what about when they exert themselves?

DOGS BARK

Huskies are bred to be sled dogs.

They're capable of covering 100 miles in a single day.

So how do they cope with getting hot?

Right, if everybody's ready, 15 seconds to start.

In 10...

nine...

eight...seven...

six...five...

four...

three...

two...one...

Go!

Ha-ha!

You might think that heat isn't really a problem

in Arctic conditions.

So to make their super-power a bit more obvious,

we've decided to race them somewhere just that little bit hotter.

Without the cold snow,

the huskies' temperature control is even more important.

Especially as they're incapable of sweating through those thick coats.

But they're still managing to lower their core temperature

by using their paws.

And there you go.

That's a win for the blue team,

and that's how important managing that body temperature is.

So let me try and get a closer look at those paws.

If I can.

With this special heat-sensitive camera,

I'll try and show you what I mean.

You can see that this dog is a fairly even temperature,

but its paws are glowing white-hot.

They're criss-crossed by a network of tiny blood vessels,

which means these pads basically work like amazing little radiators,

letting out heat and cooling the blood

before it's pumped back to the husky's body and brain.

And it's that miracle of natural design that's led to an invention

that might just help us keep our cool.

To prove it, we're going to put these ten men

to the same sort of test as the huskies.

Like the dogs, their bodies and heads are covered,

making it difficult for them to sweat out excess heat.

And we're making it just that little bit warmer than they're used to.

So, let's get cracking.

As they get stuck in, we keep cranking up the heat.

Until, like me on the saltpan,

we see them start to make silly mistakes.

It's at that point that we remove two of the men

to take part in a little experiment...using this.

This odd-looking cylinder is designed to cool us down quick.

Like a husky's paws,

our hands are filled with lots of tiny blood vessels,

but they're much deeper under the skin.

This device creates a vacuum to bring them closer to the surface,

where a chilled cone of metal quickly cools down the hot blood.

These gauges represent each man's core temperature.

And you can plainly see the effect of the glove.

More to the point, they can feel it.

Just two minutes of cooling is enough to get our first guinea pig

ready for action again...

..long before his team-mate has recovered.

It's time I tried this thing for myself.

So here goes.

That's a good seal to enable the vacuum.

The vacuum is important, remember,

it's pulling my capillaries in my hand to the surface.

They're then closer to contact with the cooling iced water,

and the idea of this isn't to cool my hand,

which does feel cool right now,

it's cooling the blood in those capillaries closer to the surface,

which is returning through my body, lowering my core,

and more to the point, lowering the temperature in my brain.

The quickest way to cool this right now is to cool that.

Right, the acid test.

I feel sharper and cooler already.

-TOY:

-Flick it!

Pull it!

Pull it!

Bop it!

Tweak it!

Twist it!

Pull it!

And so there you have it - one of the very cool miracles of nature.