0:00:23 > 0:00:25He's Dr Chris.
0:00:27 > 0:00:28And he's Dr Xand.
0:00:28 > 0:00:30Yep, we're twins.
0:00:30 > 0:00:34Do you know just how brilliant your body really is?
0:00:34 > 0:00:36Well, now's the time to find out.
0:00:36 > 0:00:39We'll be uncovering the ins and outs of what you're made of.
0:00:39 > 0:00:41I've got a big hole in my head.
0:00:43 > 0:00:47We'll be doing awesome experiments...
0:00:47 > 0:00:50..as we push our own bodies to the limits.
0:00:50 > 0:00:52It's very hard to think, it's so cold.
0:00:52 > 0:00:55..to show you all the incredible things your body can do.
0:00:55 > 0:00:57Oh, no!
0:00:57 > 0:01:01Hang around, because this is going to be fun.
0:01:01 > 0:01:04Coming up today on Operation Ouch!...
0:01:04 > 0:01:05There's a pong in the air...
0:01:05 > 0:01:07Oh, that's awful!
0:01:07 > 0:01:09..when Chris finds out why we sweat.
0:01:09 > 0:01:13I join paramedics on a lifesaving mission.
0:01:13 > 0:01:16And we turn the temperature up to show you
0:01:16 > 0:01:17how our bodies deal with pain.
0:01:17 > 0:01:19Ah, ah!
0:01:20 > 0:01:22But first...
0:01:22 > 0:01:25Hospital doctors and nurses always expect the unexpected.
0:01:25 > 0:01:28Let's see how they fix our first patient.
0:01:30 > 0:01:33In Liverpool, six-year-old Benjamin is in Accident and Emergency
0:01:33 > 0:01:37and I think there might be something wrong with his hand.
0:01:37 > 0:01:39Shut my finger in the door.
0:01:39 > 0:01:41Trapped your finger in the door?
0:01:41 > 0:01:43Yeah, don't know why, I just had a hunch it was his hand.
0:01:43 > 0:01:45It's bleeding.
0:01:45 > 0:01:47But how on earth did that happen?
0:01:47 > 0:01:51Benjamin was in the car on his way to school with his mum.
0:01:51 > 0:01:53He was enjoying the ride.
0:01:53 > 0:01:57Whoa, what's this? That's a pretty cool ride to school.
0:01:57 > 0:01:59Well, I just thought I'd do something a bit different,
0:01:59 > 0:02:02but back to reality. As they pulled up at the school gate,
0:02:02 > 0:02:05Benjamin rushed to get out of the car.
0:02:05 > 0:02:07But as he slammed the car door shut, his hand was in the way
0:02:07 > 0:02:10and chopped his fingertip off.
0:02:10 > 0:02:11Ouch.
0:02:11 > 0:02:14I looked at it and I thought,
0:02:14 > 0:02:16"He's cut the top of his finger off!"
0:02:16 > 0:02:18So, where is the end of that finger?
0:02:18 > 0:02:19I found it.
0:02:19 > 0:02:21Oh, that's good.
0:02:21 > 0:02:24Stuck on the car - it was just sticked on the car.
0:02:24 > 0:02:27Ahh, that's not so good.
0:02:27 > 0:02:30Meet plastic surgeon Dr Charlotte Defty.
0:02:30 > 0:02:33If anyone can sort out that finger, she can.
0:02:33 > 0:02:34It's bleeding.
0:02:34 > 0:02:36Is it bleeding a bit? Is it OK if I have a little look?
0:02:36 > 0:02:39I'm going to cut this dressing off, I'll keep away from your finger.
0:02:39 > 0:02:42You don't have to look again till it's mended.
0:02:42 > 0:02:47Ooh, that looks sore, but luckily not too much is missing.
0:02:47 > 0:02:50Where it's come off is basically just where the nail grows from.
0:02:50 > 0:02:54We'll just have to smooth off the bone on the end and try
0:02:54 > 0:02:57and get the skin just to cover over the end. Otherwise, you can end up
0:02:57 > 0:03:00with splinters of nail that stick out, that can be a problem.
0:03:00 > 0:03:03So there's a chance Benjamin won't have a fingernail,
0:03:03 > 0:03:06but it's more important he has a fully working finger.
0:03:06 > 0:03:08In time, you'll just have a slightly shorter finger
0:03:08 > 0:03:11and you will be able to use it completely normally.
0:03:11 > 0:03:14It's at times like this when you need a comforting word from your dad.
0:03:14 > 0:03:17That's going to be your nickname, Stumpy.
0:03:17 > 0:03:19Yeah, nice one, Dad(!)
0:03:19 > 0:03:22With the plans in place, we'll be back to find out
0:03:22 > 0:03:25how Benjamin's surgery goes later on.
0:03:29 > 0:03:31Now, we're heading to our lab,
0:03:31 > 0:03:33where we're going to put our bodies to the test
0:03:33 > 0:03:35to show you how your body works.
0:03:35 > 0:03:37Ow, that really hurt.
0:03:37 > 0:03:40Just don't try anything you see here at home.
0:03:40 > 0:03:43Ow!
0:03:43 > 0:03:45- Did that hurt?- Yes. Get off. - OK, what about this?
0:03:45 > 0:03:48No, but get off, I don't like it.
0:03:48 > 0:03:52We all experience pain. You've got over three million pain receptors
0:03:52 > 0:03:53throughout your body,
0:03:53 > 0:03:55- But some areas, like this...- Ah!
0:03:55 > 0:03:59..have more receptors than other areas, like this.
0:03:59 > 0:04:01Now, I know I shouldn't be pinching his arm,
0:04:01 > 0:04:03but it was all to explain pain receptors.
0:04:04 > 0:04:07Pain receptors are specialised nerve endings.
0:04:07 > 0:04:10They act as messengers so when they detect something painful,
0:04:10 > 0:04:12they tell your brain you're hurt.
0:04:12 > 0:04:14Pain can be really useful sometimes
0:04:14 > 0:04:17because it stops you accidentally damaging your body.
0:04:17 > 0:04:20But why is it we feel pain differently in different situations?
0:04:20 > 0:04:23Sometimes you can stub your toe and be in agony,
0:04:23 > 0:04:25other times you cut yourself playing football
0:04:25 > 0:04:27and you don't notice,
0:04:27 > 0:04:29and that's because pain is in your brain.
0:04:29 > 0:04:34This means that you can reduce the amount of pain you experience,
0:04:34 > 0:04:36and we're going to show you how.
0:04:36 > 0:04:38But before I show you this clever trick,
0:04:38 > 0:04:40I'm going to inflict a little bit of pain on Xand
0:04:40 > 0:04:43so that we can see how a person reacts normally.
0:04:43 > 0:04:45Oh, good(!)
0:04:45 > 0:04:48This is a heat stimulation thermode.
0:04:48 > 0:04:49It's a pain machine!
0:04:49 > 0:04:52I'll put it on the back of Xand's hand
0:04:52 > 0:04:54and turn up the temperature until he can't stand it.
0:04:54 > 0:04:58I'll do the same to him, and we'll see who can take more pain!
0:04:58 > 0:05:01That's a bit dramatic, isn't it?
0:05:01 > 0:05:05This medical device is used by scientists
0:05:05 > 0:05:06to test people's sensitivity.
0:05:06 > 0:05:08The end of the rod will get increasingly hot
0:05:08 > 0:05:10the more I turn this dial up.
0:05:10 > 0:05:13It won't burn, but let's see how much heat
0:05:13 > 0:05:15Xand can take by letting his body send
0:05:15 > 0:05:18pain signals to his brain, just like normal.
0:05:18 > 0:05:19- Ready, Xand?- Yeah.
0:05:19 > 0:05:21Ahh!
0:05:21 > 0:05:23It's not on yet, put your hand back.
0:05:23 > 0:05:25All right.
0:05:25 > 0:05:30That's the temperature of the probe. I'm going to start turning it up.
0:05:30 > 0:05:33Remember, we can only do this because we're doctors.
0:05:33 > 0:05:37- Yeah, it gets warm, it's warm now. - Let's turn it up a bit more.
0:05:37 > 0:05:42I can definitely feel that there's a hot thing... Ahhh... Yeah, yeah, OK.
0:05:42 > 0:05:43And a bit more again.
0:05:43 > 0:05:47Ahhh, ahhhh, aha! So that...that's really burning now.
0:05:47 > 0:05:51Yeah, yeah. Ow, ow, ow! Yeah, that's enough, that's enough.
0:05:51 > 0:05:56Xand managed to stand the pain up to a temperature of 45.2 degrees.
0:05:56 > 0:06:00It was definitely painful? It wasn't just you kind of wimping out?
0:06:00 > 0:06:02No, it was getting more painful.
0:06:02 > 0:06:05There was a moment where it was just suddenly it was,
0:06:05 > 0:06:09- "Ooh! I want to take my hand away now, that's too painful."- OK, my go.
0:06:09 > 0:06:12I'm going to try the same thing on Chris.
0:06:12 > 0:06:16Only I've got a trick up my sleeve. I'm going to distract my brain
0:06:16 > 0:06:19and that means I should be able to take more pain than Xand.
0:06:19 > 0:06:22So, let's see how long Chris can last.
0:06:22 > 0:06:25Chris, this will hurt you a lot more than it'll hurt me.
0:06:25 > 0:06:27We'll see about that. I'll use a different technique.
0:06:27 > 0:06:30I'm going to distract myself and really pretend
0:06:30 > 0:06:33this doesn't hurt, and I reckon I can take more pain.
0:06:33 > 0:06:36I'm on a beach.
0:06:36 > 0:06:38I'm on a really sunny beach. I'm feeling really good.
0:06:38 > 0:06:41You're not on a beach, Chris, you're in a lab
0:06:41 > 0:06:44with a red-hot probe sticking into your hand.
0:06:44 > 0:06:47It's not red-hot, it's barely hot. Is it on?
0:06:47 > 0:06:49How's that beach feeling now?
0:06:49 > 0:06:52The beach is quite hot now. OK, OK! I'm done, I'm done!
0:06:56 > 0:06:59Let me tell you how you did - 48.2 degrees.
0:06:59 > 0:07:01So, that beats you by three degrees.
0:07:01 > 0:07:03- No.- Yep.- Really?- Yep.
0:07:03 > 0:07:06There's no way I could have gone another three degrees.
0:07:06 > 0:07:09Yeah, it really works. So next time you've got to go to the doctor's
0:07:09 > 0:07:11and have an injection, try it and see how you get on.
0:07:11 > 0:07:15Yes, it's a clever trick. If you think of something relaxing,
0:07:15 > 0:07:18you'll find it easier to cope with pain.
0:07:18 > 0:07:20Don't feel a thing.
0:07:24 > 0:07:27It's not only teams in hospitals that deal with the unexpected.
0:07:27 > 0:07:29Wherever you are, if you have an accident,
0:07:29 > 0:07:32there'll be a medical crew on standby ready to help.
0:07:32 > 0:07:35We're going on call with the UK's emergency services,
0:07:35 > 0:07:38heading into the thick of the action to help save lives.
0:07:38 > 0:07:42Now it's Chris's turn on the front line.
0:07:42 > 0:07:44This is a rapid-response vehicle
0:07:44 > 0:07:46belonging to the West Midlands Ambulance Service,
0:07:46 > 0:07:49and it's designed to get a paramedic to the scene of an emergency
0:07:49 > 0:07:51within minutes.
0:07:54 > 0:07:58On call with me today is paramedic Ben White.
0:08:00 > 0:08:04It's not long before an emergency call comes in.
0:08:04 > 0:08:06We've been called to the home of an 84-year-old lady who's fallen
0:08:06 > 0:08:10over and pushed her lifeline button, and that's a button
0:08:10 > 0:08:14that she can press that will summon help like us.
0:08:14 > 0:08:17At the moment, we have no idea what we're going to turn up and find.
0:08:17 > 0:08:20We don't know why she's pushed the button.
0:08:20 > 0:08:22James has got his camera and I've got mine,
0:08:22 > 0:08:26so I can take you with me right to the heart of the action.
0:08:26 > 0:08:28'We don't know how extreme the situation is,
0:08:28 > 0:08:30'but Ben gets there fast -
0:08:30 > 0:08:32'in just two-and-a-half minutes.
0:08:32 > 0:08:36'It's vital we get into the house as quickly as we can.
0:08:36 > 0:08:37'The patient could be seriously hurt.'
0:08:37 > 0:08:40Hello, my darling, it's the ambulance service.
0:08:40 > 0:08:44'We're in and we find a lady called Lottie who's fallen over.'
0:08:44 > 0:08:45What happened?
0:08:45 > 0:08:48I went to the chair, it was too short and I fell on the floor.
0:08:48 > 0:08:50It was a definite sort of fall?
0:08:50 > 0:08:55- You didn't black out or collapse or anything?- No, no, no.- Okey-doke.
0:08:55 > 0:08:57'Paramedic Ben needs to examine Lottie
0:08:57 > 0:09:00- 'to check for any serious injuries.' - Any pain there?
0:09:00 > 0:09:01- No, no, no.- OK.
0:09:01 > 0:09:03- Any pain down your back?- No.
0:09:03 > 0:09:06- Have you got any pain in your hips at all?- No.
0:09:06 > 0:09:09- Shall we get you up, then?- Yeah.
0:09:09 > 0:09:11We'll pick you up together and put you on the chair.
0:09:11 > 0:09:13'When you fall over,
0:09:13 > 0:09:15'it's easy to get back up, but as you get older,
0:09:15 > 0:09:19'your muscles get weaker and that makes it much harder to move.'
0:09:19 > 0:09:21- How are you feeling? - I'm feeling fine.
0:09:21 > 0:09:23- Not dizzy?- No.
0:09:25 > 0:09:28So, Ben's just going to do some thorough checks and make sure
0:09:28 > 0:09:31all we have to do here is put her back in the chair and she's safe.
0:09:31 > 0:09:34At the moment, everything's sort of looking OK.
0:09:34 > 0:09:37Your blood pressure's very good, no injuries that we can find.
0:09:37 > 0:09:41We've checked Lottie out, all observations seem fine.
0:09:41 > 0:09:45Lottie's got carers that come in four times a day and she's got
0:09:45 > 0:09:47the pendant round her neck, so if she becomes unwell,
0:09:47 > 0:09:50she can always press it and we'll come back.
0:09:50 > 0:09:53It's good news for Lottie but now she's in big trouble
0:09:53 > 0:09:54with her friend Ann.
0:09:54 > 0:09:56She tells me off.
0:09:56 > 0:09:58Because you shouldn't have got out of the chair!
0:09:58 > 0:10:01You're never too old to be told off, is that right?
0:10:01 > 0:10:03I still get told off.
0:10:03 > 0:10:05- Lottie, we'll leave you be, sweetheart.- All right.
0:10:05 > 0:10:07Take care, bye-bye.
0:10:07 > 0:10:10If someone falls, can't get up and isn't found, even for a few hours,
0:10:10 > 0:10:13that can be really serious. Luckily, Lottie has the button
0:10:13 > 0:10:15round her neck, so we were able to be here
0:10:15 > 0:10:17within a few minutes. Ben's put her in the chair
0:10:17 > 0:10:20and now she's smiling and laughing - it's a really good result.
0:10:20 > 0:10:23Thanks to paramedics like Ben who can get to a scene fast,
0:10:23 > 0:10:26you'll never be more than a few minutes away
0:10:26 > 0:10:28from emergency medical care.
0:10:30 > 0:10:31Still to come...
0:10:31 > 0:10:35I've put on some high heels in the name of medical research.
0:10:35 > 0:10:39Things get whiffy when Chris finds out why we sweat.
0:10:39 > 0:10:41Oh, grim!
0:10:41 > 0:10:43And we'll show you how to mystify
0:10:43 > 0:10:45your friends with another mind-bending trick.
0:10:45 > 0:10:48Wow, that's amazing... and so is this.
0:10:48 > 0:10:53Into a darkened room steps a man. But this is no ordinary man.
0:10:53 > 0:10:55So, what makes him so special?
0:10:55 > 0:10:59- Is it the red hair?- No, Chris. - Is it the shades?
0:10:59 > 0:11:03- No, Chris.- Hmmm... Is it the sword?
0:11:03 > 0:11:07Well, almost. In fact, this man is hiding an amazing body -
0:11:07 > 0:11:09yes, meet the mighty Gareth.
0:11:09 > 0:11:13He has mastered the art of swallowing a sword.
0:11:15 > 0:11:18Sword-swallowing is a skill that takes years of practice
0:11:18 > 0:11:20and training.
0:11:20 > 0:11:23So don't ever try this at home, because it would kill you.
0:11:23 > 0:11:26In fact, don't go sticking anything down your throat, ever.
0:11:26 > 0:11:28It's too dangerous.
0:11:28 > 0:11:33When Gareth swallows his sword, it goes down his throat,
0:11:33 > 0:11:37into his stomach, narrowly missing his heart and lungs.
0:11:37 > 0:11:41In fact, if he made even one mistake, he'd be dead.
0:11:41 > 0:11:44And there's even more to this skill than precision.
0:11:44 > 0:11:48To do this amazing trick, Gareth has to make his body
0:11:48 > 0:11:50fight its natural desire to reject the sword.
0:11:50 > 0:11:53The gag reflex at the back of the throat,
0:11:53 > 0:11:57- that makes you just want to be sick. - Yes, I feel that just watching.
0:11:57 > 0:12:00And it's taken Gareth years to learn
0:12:00 > 0:12:04how to manoeuvre the sword past the vital organs in his body safely.
0:12:04 > 0:12:06The hardest bit is relaxing
0:12:06 > 0:12:09while doing something which is totally unrelaxing.
0:12:09 > 0:12:10You can say that again.
0:12:10 > 0:12:13I'm not sure he can, with that sword in his mouth!
0:12:13 > 0:12:15And in case you thought it was all a big trick...
0:12:17 > 0:12:19BEEPING ..it isn't.
0:12:19 > 0:12:22Now, that's amazing.
0:12:27 > 0:12:30That's not amazing, Xand. Let's go to Accident and Emergency
0:12:30 > 0:12:32and see how our patient's getting along.
0:12:33 > 0:12:37Six-year-old Benjamin is in hospital with ten fingers,
0:12:37 > 0:12:40but only nine fingertips. He was rushing to get out of the car
0:12:40 > 0:12:43when he accidentally closed the door on his hand.
0:12:43 > 0:12:46He chopped the top of his finger off.
0:12:46 > 0:12:51Having been examined by Dr Charlotte Defty, Benjamin gets gowned up
0:12:51 > 0:12:54and the surgical team prepare to operate.
0:12:54 > 0:12:58Benjamin's having a general anaesthetic to send him to sleep.
0:12:58 > 0:13:01Now, nobody's ever got to 20.
0:13:01 > 0:13:03Can you count and see if you can get to 20 for me?
0:13:03 > 0:13:07One, two, three...
0:13:07 > 0:13:10A general anaesthetic is a combination of drugs
0:13:10 > 0:13:14which put you into a temporary state of unconsciousness,
0:13:14 > 0:13:18keep you still and reduce the body's normal reactions to pain.
0:13:18 > 0:13:21- ..12... - Benjamin's still counting,
0:13:21 > 0:13:24but will he make it to 20 before the anaesthetic kicks in?
0:13:24 > 0:13:26..15, 16...
0:13:26 > 0:13:28I don't think so.
0:13:28 > 0:13:32But now he's fast asleep, Dr Charlotte can get started.
0:13:32 > 0:13:34Check out those specs.
0:13:34 > 0:13:37They might look weird, but they'll magnify Benjamin's finger,
0:13:37 > 0:13:39making it look 3½ times bigger
0:13:39 > 0:13:42and easier for Dr Charlotte to work on.
0:13:42 > 0:13:45Get ready for some fiddly finger work.
0:13:45 > 0:13:47First, Dr Charlotte has to nibble away at the bone.
0:13:47 > 0:13:50Only when it's lower than the level of the flesh,
0:13:50 > 0:13:53can the soft tissue be closed together.
0:13:53 > 0:13:56Then it's time for some stitches.
0:13:59 > 0:14:02Finger fixed and dressing on, the operation's all done.
0:14:02 > 0:14:05Everything went very smoothly. He'll be able to go home today,
0:14:05 > 0:14:08as soon as he recovers from the anaesthetic.
0:14:08 > 0:14:11Two hours later, Benjamin's awake and looking happy.
0:14:11 > 0:14:14And it's time for Dad to offer some more words of comfort.
0:14:14 > 0:14:16- How's your finger now?- Fine.
0:14:16 > 0:14:18- You sure?- Yep.
0:14:18 > 0:14:20How do you know? Cos it's not there.
0:14:20 > 0:14:23Yeah, you really do need to work on the TLC, Dad.
0:14:23 > 0:14:26Anyway, Dr Charlotte's here to check up on her patient
0:14:26 > 0:14:30- and deliver some surprise news. - He will have a nail, OK?
0:14:30 > 0:14:33- Smashing!- It'll just be a little bit shorter than it was before.
0:14:33 > 0:14:36Great result, he'll have a nail after all.
0:14:36 > 0:14:38Your fingertip will grow. It just won't quite be as big
0:14:38 > 0:14:40as the other fingertip on the other hand.
0:14:40 > 0:14:42Nice one, Doc, you've nailed it.
0:14:42 > 0:14:44Bye! Bye!
0:14:48 > 0:14:51We've got loads of amazing body tricks to show you.
0:14:51 > 0:14:55Here's how to confuse your friends' brains using just water.
0:14:55 > 0:14:59Right this is called... Xand, I need a bowl full of ice-cold water.
0:14:59 > 0:15:03Now I need a bowl full of medium-temperature water.
0:15:03 > 0:15:04And now I need a bowl full of hot water -
0:15:04 > 0:15:07hot from the tap, not from a kettle.
0:15:07 > 0:15:10I'll put this hand in the ice-cold water
0:15:10 > 0:15:13and this hand in the hot water, and I'll leave them there
0:15:13 > 0:15:15for one minute.
0:15:35 > 0:15:38And now I'm going to put both hands in the middle bowl.
0:15:38 > 0:15:42That is weird. The hand that was in the ice water feels boiling hot.
0:15:42 > 0:15:44The hand that was in the hot water feels freezing cold.
0:15:44 > 0:15:48I'm in the state of total neural confusion. Xand, what is going on?
0:15:48 > 0:15:51For the hand that was in the cold water,
0:15:51 > 0:15:54the warm-sensing nerves in Chris's skin became much more active,
0:15:54 > 0:15:57and all the cold senses were shut off.
0:15:57 > 0:16:01This fooled the brain into thinking his cold hand was hot.
0:16:01 > 0:16:05And for the hand in hot water, it was the other way around.
0:16:05 > 0:16:09So, the cold-sensing nerves in my skin became more active
0:16:09 > 0:16:11and all the hot senses were shut off.
0:16:11 > 0:16:14This fooled my brain into thinking my hot hand was cold.
0:16:14 > 0:16:19Try it out on your friends and confuse their brains.
0:16:22 > 0:16:25Now it's time for us to hit the hospitals
0:16:25 > 0:16:28to show you what goes on.
0:16:28 > 0:16:31Today we're in the Gait Lab.
0:16:31 > 0:16:35Walking. Most of us don't think about it that much, but what is it,
0:16:35 > 0:16:37what affects it and, most importantly,
0:16:37 > 0:16:39why am I wearing this outfit?
0:16:39 > 0:16:42I'm here at Alder Hey Hospital in Liverpool,
0:16:42 > 0:16:45at a special laboratory, the Gait Lab,
0:16:45 > 0:16:48and I'm going to get some answers.
0:16:48 > 0:16:52All walks are different, and your own style of walking is your gait.
0:16:52 > 0:16:56Gait Lab manager Gill Holmes is here to tell me more.
0:16:56 > 0:16:58People that come have something wrong with them.
0:16:58 > 0:17:01The doctors that are looking after them want to understand
0:17:01 > 0:17:05what it is that is making them walk in an odd way
0:17:05 > 0:17:07and what do we do about it.
0:17:07 > 0:17:10So, the more you know about someone's walk, the more that doctors
0:17:10 > 0:17:13can make decisions about how to do surgery, how to reposition muscles,
0:17:13 > 0:17:16how to help people do exercises to get them better.
0:17:16 > 0:17:19In this amazing room, sophisticated cameras
0:17:19 > 0:17:23and computer technology help create 3D models of your walk.
0:17:23 > 0:17:25So we will look at them very accurately
0:17:25 > 0:17:28and we'll describe
0:17:28 > 0:17:30how they're walking and what they're doing wrong.
0:17:30 > 0:17:33Yes, but why am I dressed in this ridiculous outfit?
0:17:33 > 0:17:37To know where you are and what you're doing, we put markers on you.
0:17:37 > 0:17:40Time to put my best foot forward - let's start walking.
0:17:40 > 0:17:42Off you go.
0:17:46 > 0:17:49So I've done my walking and now I'm going to have a look
0:17:49 > 0:17:52at the 3D model of me, and see what's going on.
0:17:52 > 0:17:57You have got a normal, efficient way of walking.
0:17:57 > 0:18:00Is this the kind of walk that a cool person would have,
0:18:00 > 0:18:02like a movie star, a dancer or something like that?
0:18:02 > 0:18:06Um...it's an ordinary walk.
0:18:06 > 0:18:07It's an ordinary walk?
0:18:07 > 0:18:12So, my barefoot walk looks good, but most of the time we wear shoes.
0:18:12 > 0:18:15Are there any kind of shoes that are bad for you?
0:18:15 > 0:18:17Um...yes, there are shoes that are bad for you -
0:18:17 > 0:18:19shoes that are too small,
0:18:19 > 0:18:22or girls tend to wear shoes that are too high.
0:18:22 > 0:18:26Have you got anything in a different colour?
0:18:27 > 0:18:30If Chris could see me now.
0:18:30 > 0:18:34Gill wants to show me how shoes can affect the way your muscles
0:18:34 > 0:18:36and joints work.
0:18:36 > 0:18:38I'm gaining a bit of confidence now.
0:18:39 > 0:18:41I think they're quite impressed.
0:18:41 > 0:18:45But as I discover, it's really hard to walk fast.
0:18:53 > 0:18:55By looking at my stick figure,
0:18:55 > 0:18:58you can see that my knees never straighten in heels,
0:18:58 > 0:19:02which has a big knock-on effect on the rest of my body.
0:19:02 > 0:19:05You can see how bad it would be for someone to wear heels
0:19:05 > 0:19:07- the entire time.- You'd expect them
0:19:07 > 0:19:10to have foot problems, you'd expect them to start to have
0:19:10 > 0:19:13some knee, hip and back problems.
0:19:13 > 0:19:17In fact, all styles of shoes can affect your body, and no matter what
0:19:17 > 0:19:22you wear on your feet, it's really important your shoes fit properly.
0:19:22 > 0:19:24I've learned that my walk is basically normal.
0:19:24 > 0:19:27We've also seen how much shoes affect the way you walk,
0:19:27 > 0:19:31but, most tragically, my ambitions to be a catwalk model
0:19:31 > 0:19:33have been destroyed.
0:19:33 > 0:19:35Thanks, Gill(!)
0:19:51 > 0:19:53In fact, the answer is C -
0:19:53 > 0:19:55enough to fill a family car.
0:19:55 > 0:19:581,264 litres, to be precise.
0:19:58 > 0:20:02Ugh! This is a case for Investigation Ouch!
0:20:03 > 0:20:06- HE SNIFFS - Ugh!
0:20:06 > 0:20:10Your feet have over 250,000 sweat glands.
0:20:11 > 0:20:14Sweat is mainly salt and water, but when you mix it
0:20:14 > 0:20:17with the otherwise harmless bacteria that live on my feet...
0:20:17 > 0:20:21and the warm, moist socks that they live in, it's a real feast.
0:20:21 > 0:20:23And what you're smelling is the waste products
0:20:23 > 0:20:27from the bacteria. Ugh!
0:20:28 > 0:20:31This is Loughborough University,
0:20:31 > 0:20:34the place to come to study all things sweaty.
0:20:34 > 0:20:37We're going to find out why we sweat
0:20:37 > 0:20:39and find out where we sweat the most.
0:20:39 > 0:20:41Using some high-tech equipment
0:20:41 > 0:20:43and this sweat collection vest,
0:20:43 > 0:20:47we're going to collect Chris's sweat.
0:20:47 > 0:20:50Now I've got to run on this treadmill in this room,
0:20:50 > 0:20:54which is kept at 50 degrees Celsius, and that is really hot.
0:20:54 > 0:20:57- If your bath was this hot, you'd burn yourself.- Off you go, then.
0:21:02 > 0:21:04I'm just jogging.
0:21:04 > 0:21:09If I was doing this outside, this would be relatively easy.
0:21:09 > 0:21:13I've just got these fans in front of me, blowing hot air at me.
0:21:13 > 0:21:16Running in a room which is 50 degrees
0:21:16 > 0:21:20is causing Chris's body temperature to rise dramatically.
0:21:20 > 0:21:24If it rose to the same temperature as the room, he'd definitely be dead.
0:21:24 > 0:21:28So I need to lose heat, and it's very hard to lose heat
0:21:28 > 0:21:31when the air around you is hotter than you need to be.
0:21:31 > 0:21:34And the only way you can do it is by sweating.
0:21:36 > 0:21:40So the reason we sweat is to take the heat energy away from our bodies
0:21:40 > 0:21:44to allow us to cool down when we get hot.
0:21:44 > 0:21:46But it doesn't work very well
0:21:46 > 0:21:49when you've put on a bin bag which stops you evaporating sweat.
0:21:49 > 0:21:52True, but you can't stop running yet.
0:21:54 > 0:21:57The sweat Chris is producing is not only full of salt.
0:21:57 > 0:22:00There are other things lurking in there, too.
0:22:00 > 0:22:04In fact, sweat is a lot like your pee - it's a lot like urine.
0:22:04 > 0:22:08You can think about that next time you lick it off your upper lip.
0:22:08 > 0:22:11Gross. I think we've got enough sweat, though.
0:22:11 > 0:22:13OK, let's stop, Chris.
0:22:13 > 0:22:17This is Professor George Havenith an expert in sweat.
0:22:17 > 0:22:21Well, it's a smelly job but somebody's got to do it.
0:22:21 > 0:22:23He's weighing all the pads from Chris's vest and shoes to find out
0:22:23 > 0:22:27how much sweat he's made and where the most sweat has come from.
0:22:27 > 0:22:30We've just measured me and I'm a kilo lighter now than I was
0:22:30 > 0:22:33at the beginning, and that is that much sweat that I've made,
0:22:33 > 0:22:36- which is quite a lot in half an hour, isn't it?- Yes.
0:22:36 > 0:22:39Typically, top athletes would go up to three to four litres.
0:22:39 > 0:22:43You, with just over a litre in half an hour, 40 minutes,
0:22:43 > 0:22:44that's a great performance.
0:22:44 > 0:22:48I'm slightly offended. I thought I was a top athlete.
0:22:48 > 0:22:52Dream on, Chris. Anyway, let's find out where you were the sweatiest.
0:22:52 > 0:22:54If we compare the different values for the pads,
0:22:54 > 0:22:57we see you sweated a lot more on your back, on your spine,
0:22:57 > 0:23:00- rather than on the front. - Really? OK.
0:23:00 > 0:23:03That's typically what we find.
0:23:03 > 0:23:06The sweatiest part is your forehead, with almost everybody.
0:23:06 > 0:23:09Usually about double the amount of the rest of the body.
0:23:09 > 0:23:11- And then the back is the second part.- What about my feet?
0:23:11 > 0:23:15Surprisingly enough, feet sweat a lot less than we think.
0:23:15 > 0:23:19Usually, we have feet in shoes, and that encapsulates the sweat
0:23:19 > 0:23:22and that's why we think they're very sweaty. But when we exercise,
0:23:22 > 0:23:25feet sweat only about a fifth of the rest of your body.
0:23:25 > 0:23:29So, we now know that Chris's feet are not the sweatiest part,
0:23:29 > 0:23:31but are they the smelliest?
0:23:31 > 0:23:34I've been running in the heat room, I've sweated masses,
0:23:34 > 0:23:37but which smells worse - the pads from my body or my feet?
0:23:37 > 0:23:41You've got to find someone willing to have a whiff first, though.
0:23:41 > 0:23:45- No, thanks.- No, thanks, you sure? Just smell my trainers?
0:23:45 > 0:23:48- No? - 'First, sweat from his body.'
0:23:48 > 0:23:50- What do you think?- Not very nice.
0:23:53 > 0:23:55It's not a great smell, I've got to say.
0:23:55 > 0:23:57OK, try a trainer.
0:23:57 > 0:24:00Ugh, that's awful, really disgusting.
0:24:00 > 0:24:01Ohh, yeah, they're bad.
0:24:01 > 0:24:03Ohhh, grim.
0:24:03 > 0:24:05I think we've got a whiffy winner.
0:24:05 > 0:24:09My feet were by far the smelliest, and I don't find that surprising.
0:24:09 > 0:24:11- These are Xand's trainers. - Oh, that's where they went!
0:24:11 > 0:24:15But it's clear that, despite our feet being less sweaty than other parts
0:24:15 > 0:24:19of our bodies, they are indeed smellier,
0:24:19 > 0:24:22and that's because they're wrapped up in shoes every day.
0:24:22 > 0:24:23But without sweat,
0:24:23 > 0:24:26your body wouldn't be able to regulate its temperature
0:24:26 > 0:24:28and you simply wouldn't survive.
0:24:31 > 0:24:35In the UK, over five million people each year have to visit
0:24:35 > 0:24:37an emergency department.
0:24:37 > 0:24:39And some cases are stranger than others.
0:24:39 > 0:24:41Let's meet the next patient.
0:24:42 > 0:24:45In Liverpool, 14-year-old Kyle has come in
0:24:45 > 0:24:50complaining of a sore and swollen hand after a run-in with a wall.
0:24:50 > 0:24:53When I woke up the next morning, it was just dead swollen
0:24:53 > 0:24:56and bruised and hurting.
0:24:56 > 0:24:58Hang on a minute, what happened with this wall?
0:25:00 > 0:25:03Kyle was in his Spanish class at school,
0:25:03 > 0:25:05in the middle of an oral exam.
0:25:05 > 0:25:07The teacher was firing questions at him.
0:25:07 > 0:25:10Como te llamas? Donde vives?
0:25:10 > 0:25:13The questions were coming thick and fast. I like the lizard.
0:25:13 > 0:25:15Que desea comer?
0:25:15 > 0:25:17A que hora es el proximo tren?
0:25:17 > 0:25:20Uh-oh! He'd forgotten everything he knew.
0:25:20 > 0:25:23Frustrated and angry with himself, he shot out of the classroom.
0:25:24 > 0:25:28It was then that the wall, completely unprovoked,
0:25:28 > 0:25:31suddenly and brutally hit Kyle's hand.
0:25:31 > 0:25:34OK, Kyle whacked the wall with his hand. Ouch!
0:25:35 > 0:25:37It was a stupid thing to do.
0:25:37 > 0:25:38Si, estupido.
0:25:38 > 0:25:41But that hand does look pretty painful.
0:25:41 > 0:25:43I was doing swimming yesterday in school, PE.
0:25:43 > 0:25:46That hurt, just touching the water with me hand.
0:25:46 > 0:25:48Best get you looked at, then, Kyle.
0:25:49 > 0:25:54You'll have to 'fess up to Sister Jo what you've done, though, mi amigo.
0:25:54 > 0:25:57I had a Spanish test and I failed,
0:25:57 > 0:26:00so I got angry and disappointed and I just hit the wall.
0:26:00 > 0:26:02I can see the bruising there.
0:26:02 > 0:26:06Right, what we'll do is send you for an X-ray and take it from there.
0:26:06 > 0:26:08X-ray it is, then,
0:26:08 > 0:26:11and I have a feeling it's going to be more than a sprain.
0:26:11 > 0:26:13While we wait for the results, come on, Kyle,
0:26:13 > 0:26:15let's have another go at that Spanish.
0:26:15 > 0:26:17How do you say "I've hurt my hand"?
0:26:17 > 0:26:21And with the walls trembling with fear in case he gets it wrong...
0:26:21 > 0:26:22Mi mano es malo.
0:26:22 > 0:26:25That'll do. Walls relax, he's got it.
0:26:26 > 0:26:30Enter Dr Bimal Metha. He's been checking out
0:26:30 > 0:26:33Kyle's X-rays to find out why that hand hurts.
0:26:33 > 0:26:36If you look on this side, you can see it's nice and smooth,
0:26:36 > 0:26:37but here, there's a funny bump.
0:26:37 > 0:26:40Yep, that funny bump might not look like much,
0:26:40 > 0:26:44but it's actually a painful fracture. Better break the news to Kyle.
0:26:44 > 0:26:47As expected, cos walls are harder than bones, the wall's won.
0:26:47 > 0:26:51Your bone has broken. That's called a boxer's fracture.
0:26:53 > 0:26:57Boxer's fractures are one of the most common hand breaks
0:26:57 > 0:26:59doctors see - usually caused
0:26:59 > 0:27:02when a closed fist hits something immovable, like a wall.
0:27:02 > 0:27:04They can be extremely painful.
0:27:04 > 0:27:07So, the next time you feel frustrated,
0:27:07 > 0:27:09you might just want to stop and think.
0:27:09 > 0:27:11It's not a serious fracture.
0:27:11 > 0:27:14The main thing is, it's going to be sore in the next two to three weeks.
0:27:16 > 0:27:20Luckily for Kyle, there's no big plaster cast.
0:27:20 > 0:27:21OK? Just keep that clean and dry.
0:27:21 > 0:27:24Fingers strapped together and he's on his way home.
0:27:24 > 0:27:26BOTH: Adios, amigo.
0:27:26 > 0:27:28Bye!
0:27:30 > 0:27:31Next time...
0:27:31 > 0:27:36Things get chilly when I enter a room colder than anywhere on the planet.
0:27:36 > 0:27:39I explore the inside of Xand's head.
0:27:39 > 0:27:41If Chris gets this wrong, he could kill me.
0:27:43 > 0:27:45And this man reveals an extraordinary body.
0:27:45 > 0:27:47So, see you next time on...
0:27:47 > 0:27:49BOTH: Operation Ouch!
0:27:51 > 0:27:56Subtitles by Red Bee Media Ltd