Computer generated transcript

Warning!
The following transcript was generated automatically from the content and has not been checked or corrected manually.

We're gonna look at cold injuries now, um, and I've broken it down into frostbite and non freezing cold injuries and the definitions really are whether the tissue actually freezes or not. So, whether ice crystal forms, um, and when it does, it's frostbite and when it doesn't, it's non freezing cold injury. So, um, looking at when you get frostbite, obviously, it's going to be in a cold situation. So if there's a chance of you getting hypothermia, then there's a chance of you getting a cold injury at the same time. Um, and I like to think of frostbit as the way of, um, the body's sort of a side effect of trying to protect itself. Um, and we can, it's completely preventable. It's definitely something that you should not, um, really a feature at all in any expedition now because we know so much about it, we know how to manage it and we know how to prevent it most importantly. So, um, situations where you might need to consider it and, and then therefore start preventing it are looking at where you're going, what you're going to be doing. Um, the environment that you're gonna be working in. So yes, there's the absolute air temperature, which is obviously important, but much more important on top of that is the wind chill and this is the wind speed. So we know that the obviously the faster the wind speed, the cooler is going to be and it's going to take away that heat a lot faster. And then that's not only a risk of hypothermia but um, frostbite and that might be due to the activity that you're doing. So, if you're uh skiing, for example, you're going to be traveling a lot faster and therefore the wind speed over you is going to chill you even more, particularly when you're exposed, your feet or your fingers are going to be exposed. Um Think about the kitten equipment you're going to be using. Um And how that how you can sort of mold that to the situation and protect your tissue from getting freezing from literally freezing and from getting cold. And then also think about altitude. Um You know, we know the altitude is a significant factor. It already reduces the amount of oxygen increases the viscosity in the blood. Um And that all sort of plays a huge factors into the development of frostbite and cold injuries. And we're looking that a bit more detail in the pathophysiology. So who gets frostbite? Well, here you are, this is a little bit of a an activity for you all. Um Just pause the video and think about what kind of behavior a physiological and mechanical aspects will influence the risk of getting frostbit. Um I'll give you a clue. Things like behaviors are um, the kitten equipment that we might be using. So, uh cause a video and write down a few of each of them. So hopefully you've now written some down. So, um, let's look at behavior first. So clothing, um, obviously the kitten equipment they're going to take with them, have they got the right gloves, have they got things made out of the right materials? Um Will example, for example, over cotton, which isn't very good. Um Are they going to be taking any alcohol or drugs? Are they in a situation where they have access to it? Especially, um reprobates that you might have on your um on your team, people who've got psychiatric illness. Again, this part of your screening, are they going to respond appropriately to the situation to the environment? And then um smoking, we know smoking is a big risk factor for frostbite. Um probably not so much in the acute phase, but it's definitely, if they, if they are a smoker, then you might want to make them aware of it uh that they'll need to protect themselves from getting frostbite more um physiological. So, uh genetics, where were they brought up um being dehydrated and uh low sugar levels? Um So again, are they maintaining their own nutrition? People have arthritis on drugs, um especially people who've had previous frostbite record injuries, they are significant risk of damaging that same uh tissue again. Um So really just again, that's part of your screening process and then mechanical. So looking at constructive clothing, are they, you know what kids and equipment are they wearing? Um lots of people will just put on lots and lots of more layers, which is great, but make sure that they're still getting the blood supply to it. Um Have they got layers over um their skin when they're touching things? So like temples or any metal bits and pieces. And then again, people who have um who immobile. So if they're um either injured in any way or um or even worse, really bad is people who have got reduced sensation in any element. So, in their toes or fingers from uh vascular disease or diabetes and things like that. So think about that again, when you're doing your screening and I've kind of highlighted these um areas which you can do something about or you can at least prevent them. So you're having the right kit and equipment. Um making sure that people are dehydrated, not dehydrated, they're well hydrated that they've got sugar levels, maintaining their nutrition. Um and um basically doing your screening before. So making sure that they are aware that they might be an increased risk of frost bite at cold injury prevention prevention is far better than cure and all cold injuries are completely preventable. So I've just listed a few things. Um This is a good uh sort of activity for you all to do to think about how you can prevent cold injuries. Um Looking about what, you know, what kind of clothing kitten equipment is best. Um I'm a big advocate for will um will is super warm, but it's also really warm when it's wet as well. So this is just a picture to show that the uh the cotton on the right is has shrunk compared to the cotton. So it's compared to the wool on the left. Um So, you know, think about where you're going, what you're gonna be taking, what the condition is going to be like. Um what kitten equipment is best and always, always do research nutrition. Again, I'm sure Rin is gonna talk a lot about this, but we know carbohydrates specifically um have a big impact on the effect of um uh certainly altitude, but also the uh cold injury prevention. Um and with that comes hydration and you'll hear more about that in the pathophysiology side of things as well, early recognition and um early management and just generally preventing it. So this is one of us from our trip across Antarctica and we obviously we um created, we wore goggles, we try to protect our face, but we did everything we could including this neoprene over the front just to give us that extra layer against that wind chill factor. Um but it also meant that we had to actively inspect each other's faces. We had a buddy, buddy system going on. We wanted to recognize things early and then manage them um so that they prevented, stop them getting worse. Um And all of that is all to do with your planning, your preparation and your, your S O P S, I guess your standard operating procedures, how you as a team function to recognize things, getting uh getting cold and then going in the wrong direction and then actually having early interventions so that you can just carry on and it won't become an issue uh in the future, like um excessive sweating. So I put that as something to be aware of because if you've got a big team, so I went up Killy with a team of 32 people and the split was huge. There was some really rather overweight people um struggling going quite slowly and then some really fast people and, and thin individuals who were then having to go at the pace of the slowest person. Um and you ended up with a real mix. So the overweight people were at risk of uh sweating too much and then getting wet and cold. Um And we know that that has caused uh expedition failures in, especially in Antarctica where people don't wear the right kit, they sweat and then the sweat freezes and then they end up either getting hypothermic or getting a cold injury, I mean, and equally at the other end of the scale, you've got the thin individuals who, who wanted to go really fast but weren't able to. Um, and they were then essentially getting cold from, from not moving as much and not using up as much energy. So they're at risk of hypothermia and cold injuries as well. So it's stuff like this where you might be required to just help mediate the situations and advise people on how they can protect themselves from hypothermia and cold injuries. So, let's look a little bit about the pathophysiology of frostbite. Um As I've said, frostbite is the result of the body protecting itself against hypothermia and at 15 degrees C, um we obviously the skin temperature, um the, the vasoconstriction reaches its maximal point. So it can't restrict any more than this below 15 degrees vasoconstrictions is actually interrupted. So you get these rhythmic bursts of visa dilation because the body knows that needs to keep getting blood supply and oxygen and nutrients to the tissues peripherally. Um And it will occur sort of about 3 to 5 times an hour each for about 5 to 10 minutes, you might get this flushing um in the extremities. Um These are actually much more frequent and longer in individuals who are climatized. So, um there are, for example, in Mongolia, there are some fishermen who work um in cold water all the time in um freezing conditions and they have really good bursts of vezo dilation to maintain their, their blood supply to their fingers. Um And yet us in, you know, relatively warmer climates won't have uh such a good acclimatization. Um at 10 degrees C, um the sort of neurapraxia starts developing um loss of cutaneous sensation and essentially at seven degrees, the nerve conduction um completely stops. So you're going to get complete numbness, obviously, um lower than this. Um get completely negligible cutaneous blood flow, which I've sort of tried to demonstrate by this ice shelf. Um And this is when the skin really begins to freeze. So without any appropriate circulation, skin temperature would drop at rates exceeding sort of not 0.5 degrees c per minute. So really rapidly. Um and obviously, the smaller vessels freeze much quicker than the larger vessels. Um And then obviously, the venous system freezes faster than the arterial system. And that's obviously just because of the flow rate. Um And that's quite significant when we come onto looking in more detail about the pathophysiology. Um So which bits of you will get cold, which wherever you most at risk of getting hypothermia. Well, yes, you've got basically all the endpoints, the extremities. Um So your ears, your fingers, your toes and your nose. And gentlemen, um let's not lie. Let's not forget this is very important. You do get a frozen, um You can get frozen. Polar penis is a real thing. So do make sure it's wrapped up. Um make sure flies are done up, make sure uh it is well looked after because it can happen. So let's looking a little bit more detail. Um, frostbite is a freezing injury that's kind of divided into four overlapping pathological phrases, phases, stories. So you've got the pre freeze phase, um the freeze thaw or vascular stasis and late ischemic and we'll go into each of these um sort of phases and what that means and how it occurs. Um But it is worth remembering that. So, frostbit pathophysiology. So let's look, it's, it's easy to look at it from a direct and and indirect um sort of perspective. So when you've got direct cell damage, this is normally from the crystal formation. So when you've got the fast, rapid freezing, it will create crystals inside the cell. Um and things that might develop from fast or how fast um freezing occurs is when things like when you're actually touching things that are wet and freezing. So like um gasoline evaporating off your fingers and freezing conditions that's going to cause this fast um freezing and crystal formation inside the cells. Um Other scenarios are. So, um there was a couple of people when we were in Antarctica who got frostbite just from touching the temp polls and anything metal. So they just didn't really think about it. Um So again, if you're advising people make sure that they've got um protective layers between, even if it's just those simple sort of glove liners, something to protect the, the the cells uh from this really fast freezing mechanism. Um And then you've got the slow process. So um this is much more common. It's results in the crystals forming outside the cell and you've got this gradual cooling of the tissue. So this is more likely to be happening on the mountain side. Um And you know, when your, when your body is trying to protect itself from getting cold and the, the vasoconstriction occurs. Um And this is where the extracellular fluid begins to freeze. Um And then that causes the extraction of the intracellular fluid via osmosis. So it draws it out and the cells, the cell shrinks and then crystals form on the outside. Um Now, crystals are really sharp. Um And it sounds crazy that actually those actually forms a sharp edge when they're that small, but they do and they can rupture the cell membranes causing further cell injury. So, um uh that's essentially the way that the direct and indirect crystals damage the cells um when the cells are damaged and the membranes are ruptured or their cell bursts or shrinks depending on which, whether it's fast or slow. Um then you get electrolyte shifts. Um and then um ultimately, cell death essentially, but don't forget, you've also got that burst. So that intermittent phase a dilation um which then can cause this uh sort of reperfusion injury as well. And the inflammatory response because you're getting all those cytokines, getting to the damaged area, noticing that it's damaged and then wanting to try and fix it. Um And this is really important. Why don't rub the frozen tissue? So if you're cold, don't rub it because you're just causing more damage. But with those crystals by rubbing it and damaging the cell membranes, so just don't rub it and looking at the indirect process, um you've got, I'm pretty simple minded and I have to look at things from analogies. Um So when you have indirect um sort of cold injuries, um it's this is essentially from the, the blood not getting to the cells. Um And then they cause you've already got the actual cell damage from the direct and then you've got indirect from the vascular stasis. So essentially everything starts constricting and cooling down and the blood becomes thicker, more viscous and it basically doesn't go anywhere. So that's how I've uh and analogized it to traffic jam. And then you get this leakage of serious fluid, increased blood blood viscosity. So everything is um really thick and uh then you get thrombus formation as well. And then uh so you've got these, all these cars which are causing this thrombus is complete pile up. Um And then uh the road disrupts even further and this is where the microvasculature. So all the capillaries become completely uh broken. Essentially, they are ruptured, their endothelial cells are damaged, the just completely disappears. There is no road any longer and this is quite nicely demonstrated by this um, technician scan. I guess that's how you pronounce it. Um And this is a rat poor that shows services got the dye showing the vascular chair on the picture above and then it was frozen. Um And then you can see the destruction of the microvasculature afterwards. So this poor rats poor has just completely destroyed all its microvasculature. And this is essentially one of the most um significant reasons for the cell death because they just even after the the thawing process, there just isn't the structures and the network to get the nutrients back to the cells that have been damaged and obviously, that includes warmth, oxygen and nutrients and taking away the toxic substances. So this is why we end up with the indirect or the late ischemic phase. So let's look at a little bit of a classification of frostbite. Um So it's quite difficult to differentiate really early on um what level of frostbite it's likely to be. Um it will definitely develop over time when it becomes more obvious, but sort of stage one would be numbness and redness. So you might get a white or sort of yellow, firm, waxy plaque developing in the area of their injury. Um And you don't necessarily get any gross sort of tissue infarction. Um but there might be some sort of sloughing of the epidermis. Uh and you might get a little bit of uh mild edema as well. Um So you can see on this chap here, he's got this white waxy patch, which is um, clearly a sort of a type one frostbite. And then you've got type two, which is the super superficial skin, um, sort of freezing. Often we'll get a clear milky fluid in the formation of blisters. Blisters might uh sort of form a couple of days later. Um And you'll get some surrounding erythema and edema as well. So, again, might develop a little bit bit more obvious over time. Um And then three and four, um again, these are likely to be identified a lot later and you've got, um, obviously it's deeper tissue this time. So each phase is the, the different level that which it's freezing. Um And you might get hemorrhagic blisters, which indicates that it's really gone down to that particular dermis and, and the vascular plexus underneath us, it's involved frozen all the way down to there. And then for uh grade four is when it's gone completely through the dermis and um into that sort of a vascular tissue with extension, possibly down into the bone as well. So when the bone freezes as well, that's when uh you know, it's gone really deep and it's, it's pretty bad. So this is just a couple of pictures, um, a little bit more information about the different differing degrees. So this is actually my hand in Antarctica and, um, I, I didn't, I mean, there's a bit of an odd place in my fist so it's a bit of an odd place to get frostbite. Um, and essentially I first noticed it because it was really itchy. It was really, really itchy on my, this is my little finger, my right little finger knuckle. And, um, I was like, that's really odd. I was thinking I've been bitten by something, but there's not many insects that survive in Antarctica. And then it's, um, it's started forming this blister and it was quite swollen and I suddenly realized that actually it must be frost bite or the beginnings of frostbite. And I couldn't work out why I got frostbite there because my fingers hadn't been particularly cold. It's been an odd place. You think it'd be the finger, sort of the tips of the fingers. Um And then I realized that actually when I get really, really cold, really cold fingers. So I was anticipating getting freezing and put on loads of gloves and I put pokies onto my polls and the Portuguese had a metal zip underneath and actually this was where so my knuckle was resting on the zip despite wearing three pairs of gloves or three layers. Um, the metal got so cold that it actually froze, it was freezing, that small amount of tissue that was in contact with it. Um, but it's, it's not an obvious place. It's didn't really, I didn't feel the cold there. I guess it was always like a cold burn. Um, so you just think about again that prevention, what are you going to be wearing or in contact with and, and look out for this because as soon as I realized that it was easy to, um, to manage it and I just, I put on a, uh, I took away the pokies and, and managed it and never, never luckily developed further than that. Um So, yeah, it was sort of a uh, very white yellow, slightly raised plaque. Um, and it started to blister in my, in my situation, um, and second degree. So this is likely to form the blisters like two forms of 12 to 24 hours afterwards. And you might get the skin just drying out and sloughing off. And if it's clear fluid, you know, that it hasn't gone down to the vascular layer. So, um, that's a good sign. Um, you might get the, uh, blisters that you might need to deal with by either aseptically um, draining them or if necessary, just leave them if, if, if you're at risk of, if you don't, can't do it aseptically because obviously you don't want to introduce further infection or an infection, fourth degree, um, sort of level where you've got the freezing has gone right down to that vascular layer. Blisters will form and they'll often be sort of dirty bloody blisters, which proves that they've gone, it's gone quite deep. You won't necessarily be able to tell how deep it's gone, whether it's gone to the bone. Um, so that's why we kind of keep it as a, uh, superficial in the field or deep in the field. Um, and that's, yeah, that's when you'll get blisters forming a bit later, significant risk of infection here, especially if the blisters burst because obviously it could go all the way down to the bone, there's exposure down to the bone. Um, and you could end up with bone infections as well. Um Give your patient's some sort of an idea. Um, probably not wanting to freak them out on the mountain side. But, you know, you might, these are kind of the chances of looking at, um, tissue long term tissue damage, um, an amputation, nothing should be amputated on the side of the mountain. Um, I have uh uh interesting story of a gentleman who was back in 2006 and he was tracking to the South Pole. Um, I got a lot of information on from him about what not to do when you go to the South Pole. Um, and essentially he got frostbite in his fingers and, um, or in his, in his thumbs actually. Um, and for some reason, they got amputated there in Antarctica. I'm not entirely sure why because everybody should know that, you know, freeze in January and he amputate in July. So it's a long, long time between um any surgical input and an actual freezing. And that's to allow enough time for your body to try and recover as much of the tissue as possible. Um But yeah, unfortunately, this guy lost his thumbs in Antarctica. Um So that's a little bit about the prognosis. So, looking at the management side of things, um we'll look at the field management primarily because uh that's where we'll be, is in the middle of nowhere. Hospital management is very specific and I would highly highly recommend getting um advice from a specialist early on. So if you think you're going to somewhere where you are likely to come across frostbite, so really high altitude or the activity that you're going to be doing, find a specialist who is prepared to be your reach back, so you can ring them, they know where you are, they know what you're doing and they can advise you without too much difficulty, even if it's via a sat phone or via text or something. Um It's really important to make sure you've got your own reach back services established. So let's look at the Wilderness Medical Society practice guidelines. Um Again, this is uh from the 2019 updates um readily available on the internet. So I do have a look, especially going to somebody somewhere where you're likely to come across prospect. Um And is it worth considering what you're going to be doing? So where you are, um could they be hypothermic as well? How far away from help are you, how are they, how are you going to be able to extract them? Um Do they need to be able to walk out of there? Do they need to, can you get helicopter out of there? Um And most importantly, is there a risk of the injury refreezing because that will all affect your management? So, looking at the field management side of things, uh first thing you're going to want to do is get them into shelter. So, um especially if there's a risk of them being hypothermic. If it's been a slow process of vasoconstriction, um freezing that tissue, then get them into shelter and prevent them getting any colder, um remove wet clothing. Um get rid of anything that's going to make it even colder. So like jewelry which conducts heat away, obviously freezes things. Um get that away from the, from the damaged tissue. Um do not rub it. You might see lots of um mom's rubbing their kids hand when on a cold day and breathing on them, don't do that is only going to make the injury worse um by damaging the cell membranes with those ice crystals. Um And do you use each other's other themselves or their own body heat? So this is a point where you shouldn't really get to, um, you know, frostbite is completely preventable, as I keep saying, um and it really shouldn't get to the point where you're having to re warm it, um, in between 37 39 degrees because it's, it's got that bad. You should try and prevent the frostbite occurring. So as soon as anyone feels, uh, slightly numb or, uh, there's a freezing part, you know, you notice in the buddy, buddy system that somebody has got a white plaque on the face, you want to manage it directly there and then, um, don't let it get worse and worse as I'm sure you will hear from a key member who has experienced it himself. Um I think you'll hear about him from him this week. So if you, if it has completely frozen and you're literally managing it in the field, then you can start rewarming it. But the most important thing is if you're going to start rewarming it in the field, you must make sure that there is not a chance of it being re frozen because there's nothing worse than uh, tissue that has, um, frozen and then, uh, thought and then frozen again and then thought it just makes it a lot worse. So if it's frozen and you, you're not going to your, I'm not going to be able to re warm it without the risk of it freezing again, then it's almost better to just keep it pretty cold. Um But this is again, something you can get advice from even in the field with your sat phone. Or your uh Garmin E Treks or whatever um communications methods you have, make sure you can get in touch with somebody who can advise you on the situation that you're in. Um you can start giving Ibuprofen. So we know that Ibuprofen will reduce the uh sort of the rewarming profusion issue, um injury. Um And uh the same with pain medication is, you know, I'm sure all of us have had some elements of rewarming when our toes of being completely numb and it is super, super painful. I've actually even thrown up once because I was in so much pain when my toes were rewarming once. Um, it's, yeah, it's, you want to try and minimize their discomfort when they're already worrying if they're going to lose their toes or fingers or thumbs or whatever it is. Um, and like I say, protect from refreezing and direct trauma. So, really do if you, if you've made the decision that you're going to carry them out, um, like many people do come off the, um, you know, Everest and the Himalayas, um, on the stretches then make sure that you, you yourselves are going to be protected and not get injured from carrying this person out. Um, so yeah, protect them and yourself and then looking at the hospital management side of things unless you're working specifically somewhere, but it's, um, where they've got this treatment, they'll do the same sort of thing. They'll, um, they'll obviously manage the hypothermia side of things, they'll start rewarming, uh start giving um nsaids that Ibuprofen. Um And then they might, they'll often have a scan straightway to a technician scan and um they can then start iloprost therapy. So I'll process is quite specific. Um And it will, it's been proven to um to reduce the frostbite damage getting even deeper. So that's what is, if you give iloprost within 24 to 48 hours of the rewarming is going to increase the chance of the tissue surviving. Um And that is where the technician scan is useful because it can show how much of the tissue is going to still be viable. Um And they'll, there's a very set protocols on this. Um They can, you know, within five days, seven days, you can get a better idea of how much tissue is going to um survive with and without the iloprost and how far you may end up having to amputate in the future. Um Some really fascinating things that they can do now, um things like this gentleman had frostbite in his fingers and I think it was taken down off the mountains in the Himalayas, um had all the therapy and then they actually um sort of sewed his fingers into his uh basically into his side for a few weeks to say that they try to recover as much of the vasculature as possible. Um So that they increase the chance of his fingers sort of not being damaged in the long run. Um, and as I say, it's freezing January and amputate in July because you don't want to be like this poor gentleman in the South Pole who had his thumbs amputated. And then what was made it worse is he came back to the U K where they tried to replace his thumbs with his toes because obviously the thumb is what gives us our hand, our, um, our opposable thumbs and he ended up having his toes amputated to put on her, his hands. Uh And so he then had to learn to walk again because he didn't have any toes or didn't have two toes. And then actually, unfortunately, the toes didn't take on his hands. And so he ended up with no toes and no thumbs. Um, luckily he's done pretty well out of it. But, uh, yeah, it was all from basically, uh an error made in the field with some sort of attempt amputating on the ground, which is completely not necessary. Um, over time, um, the tissue that has died and that isn't going to, that hasn't got the vasculature back and it's, you know, there's, there's a very definitive cut off lines, it becomes quite obvious, um, the tissue, but beyond that will sort of mummify in turn black and likely to auto amputate. Um, the majority of people who have got frostbite will know this themselves. They'll know that if it turns black and it's, it's gonna likely to fall off itself. And uh, but it's worth just bearing in mind that they may not be um, as intelligent as you would like to assume. I had, I was dealing with one patient who uh this is uh this thing happened, he got frostbite in his uh in his toe and it uh was turned black and we said your toes going to fall off and he said, okay, that's fine. We were quite surprised that he was took it so well until he asked. So when, how long till when you tow grows back? Um So just don't assume that people um have moderate intelligence. Um That's kind of a snapshot of frostbite. I think at the end of the day, it's about preventing uh frostbite is completely preventable. You shouldn't need to get it, you shouldn't ever get it. Um uh Actually doing everything you can to manage, preventing it, spotting it early and then treating it as early as possible will prevent uh significant uh tissue damage and ultimate um amputation and things like that. So, uh definitely uh as a medical expert on an expedition, you should be all over this and be able to prevent and advise um just to touch on non freezing cold injuries. So this is a huge issue in the military. Um We have NFC I is a sort of common term, a big payout for individuals who, when, when it means that they can't function in the army anymore. You can get a big payout for it as well. So, um, it's a bit controversial because there's not actually necessarily any formalized method of diagnosis is, um, the Institute Naval Medicine down in Gospel. They do all these, uh, tests and nerve conduction studies and things, but there's controversy over whether they are actually accurate or not and it's whether it can be proved to NFC I or not. Um, but generally the, the, um, non freezing cold injuries are kind of, these are the top ones. Uh, so trench foot pony Pernio, sorry and Polar Thigh. Not many people have heard of Polar thigh. It's quite specific and I'll talk about about that because it was relevant to us in Antarctica a little bit about a non freezing cold injuries. Um, it's the sort of process isn't really very well known. Um, we know that it happens in warmer conditions. It doesn't have to be freezing outside. Obviously. Um, it's probably most likely to be from prolonged exposure to cold. Um, in the military, we have to say that there has been one specific, um, incident so that for example, they were, they got really called on one exercise, um, usually in wet conditions as well. So, um, probably when there's been an element of core temperature drop as well, um, we know that it can damage the small vessels. Um, but most importantly, it causes some nerve damage and this is a photo which I would argue actually looks more like uh some sort of freezing cold injury. But this is one of the examples that the military give um as to what non freezing cold injury may look like. Um I would argue that actually the majority of patients I've seen they can't, there's no, there is no damage. Um You can't see anything necessarily, especially when they come in to you to see you a few days or weeks later. Um, but generally it will, um, it will develop to be sort of prolonged nerve damage so they can get hyperesthesia, um, you know, extreme sensitivity to cold, um, and it can cause, you know, some severe pain. So we've got quite a lot of guys who are on, um, a Triptolin of gabapentin, um, for nerve pain. Um, and then, you know, if they can't handle a weapon for us, um, that means that they could be out of a job as well. So, um, there's quite a set sort of process in the military of how to manage people with NFC. I, um, but generally outside died in civilian world, not many people sort of come across it, I think probably because they're less likely to be re exposed in such a short time to the cold conditions, but it's just worth bearing in mind. Um, finding out again before you go on an expedition that have people had any cold injuries before. Are they more like to come across it again. Um, and then you can at least look out for them and try and prevent it. Um, but Pernio was like the Chill Blaine's. Um, and it's generally an inflammatory reaction to the cold. Um, you, once you've had it, once you probably likely to get it again, it might occur in the same place. Um, it can present uh with these sort of inflammatory splotches on, on the damaged tissue. Um Some people are more like to get it if they've been exposed to cold and then rewarmed rapidly. Um But you can man manage it with topical steroids. Um If it's, if it's an issue in the cold, once it's rewarmed, it shouldn't be an issue again, especially if they don't go back out into the cold for a long for a while. But if you, if you've got it, once you're more likely to get it again, um It's kind of a similar to the polar thigh. This is relevant to us because a lot of skiers in Antarctica and, and Scandinavia can get it and it's when you're exposed to the call for a really long time. Um We think it's to do with necrosis in the fat tissue. So essentially the, it's mainly called polar thigh because it occurs most commonly on the thigh. Um And it's where the, the subcutaneous fat is such a good insulator. It prevents the heat generated and the muscle underneath reaching the skin on the outside. So then you end up getting um sort of, I guess an inflammatory response from the freezing and from the continuous cold and then possibly to do with friction as well. So we think, you know, with rubbing, especially in the skiing motion walking. Um the tissue that especially will, which can be quite um harsh and fibrous can damage the, you know, add friction which then further damage is it. Um And this is one of the girls from our trip. Um I did a little bit of a log of hers. So this was in February 26th of February. Um, she started getting this what looks very much like Pernio, not painful, just quite itchy um, over the outside of her thighs. Um, and then it's on the third of March and this was the day we came into the, we've been out for three weeks, I think, not, not, not having ever gone inside, gone into any kind of external warmth. Um, and it wasn't, again, wasn't painful at this point, but you can see, um, here it's just beginning to dry out a bit and if it dries out, it can, um, end up sort of ulcerating and then you're at risk of getting infection as well and this was a month later where it has pretty much completely healed. It was still quite bumpy underneath, but she had not been exposed to the cold any longer, so it wasn't getting worse. Um, this is what can happen. Uh, if you don't. So this poor woman, this isn't one of us. It was somebody else. Uh, she got polar thigh. This is from her trip in Antarctica and unfortunately, ulcerated, she didn't manage it particularly well. Just kind of grizz did it. Um, and then, uh, you know, is that's at risk of getting infected and then septicemia, especially in the middle of nowhere. You don't want to be managing that. Um Again, it's completely preventable. Um at the early stages using topical steroids um to manage it and protect it from further friction, protected from the cold even more. We were wearing um uh skirts. So um down skirts over the top just to protect it a little bit more from, from the cold. Um And actually, you can see here this guy, he's got sort of elements of polar thigh, um or that, that process happening elsewhere. So this is probably where he, his harness was um rubbing on his shoulders as well. So he's got it all over his upper body. So it doesn't just happen on the thigh. It happens where they're subcutaneous fat. Um, similar is trench foot. So this is um again, quite common in soldiers, less so now than it used to be, especially now we have foot parades. Um And you have to expect foot inspections. Um But it's when people are exposed two wet conditions. So generally socks, so when socks are dirty and wet, they don't obviously hold the heat but dirty clothes also, um, don't allow the heat to sort of remain in them as well. Um, again, it happens in milder conditions, it's not freezing. So obviously the water isn't frozen, but they are just generally wet, they don't allow to dry out. Um, and then you get soft tissue damage and it can cause nerve damage as well. Um, and with soft tissue with the soft tissue damage as well, there's a risk of infection and, um, and it can be really, really painful. So if they're, especially as a soldier, they're expected to walk out um or much around or run around with a weapon, then uh then they, they are increased risk of um not being able to do that and then not be able to do their job. So, um, it's all completely preventable. Um And, um, you know, these are, this is kind of education that you can, you can give to anyone that's going on an expedition before as well. Um So that they can manage it themselves. It's all self management and by all means you can always add in some foot inspections of your own team if you really want to. Um So I hope that has uh kind of given you a, an introduction to non freezing cold injuries or, and freezing cold injuries. Um And I think the key message here is that all of them are preventable. Um You shouldn't ever, nobody should need to get hypothermia. Nowadays. We've got so much kitten equipment to prevent it. Um You should be able to recognize it early. Um And, and then avoid any further injury by refreezing and most importantly, get specialist advice early. Um And there's, there's lots of people out there, I'm sure uh Lucy will be able to give you some names of individuals as well. Um uh Center in Coventry as well, which is basically the Uk's Best advice Center for Freezing Injuries and vascular um surgeons run that. So, do you get in touch, find out who your resources can be before you go on a trip so that you're not having to do it whilst you're there on the side of a mountain with a sat phone. Um and I just, I love this photo. Is it a green uh jelly baby gone black or is it a black jelly baby? Gone green? Who knows? So, um Thank you very much and take care. Yeah.