Monday, 27 February 2012

Igloo Man

Swedish man was/was not trapped in his car for two months/a bit living on only snow, but maybe other stuff

Peter Skyllberg may or may not have survived an ordeal which may or may not have been a miraculous survival story.

Frankly I don't care if this recent survival story is true or not, but it does raise some interesting survival questions. Let's take them in a pretty standard order of priority; that is to say, let's deal first with the things that would kill us first.


Apparently, he was stuck in the car, under two feet of snow. Well, it wasn't an avalanche, so I have to wonder how he managed to get stuck inside during even the heaviest of snow storm. Might have been worth checking the weather forecast to if there was an indication of such a storm for him to have been so quickly snowed in. Maybe packing a snow shovel would have been an idea. There was no mention of him being knocked out, and even if he slept through his snow storm, it's not beyond the wit of man to open or even break a window and poke your way out. He had to have some form of ventilation, or he'd had suffocated.


They say the temperature went down to -30°C, but let's assume that's the press playing the statistics cards. I had a quick look at the statistics for the area and it turns out.
The month of January is characterized by essentially constant daily high temperatures, with daily highs around -3°C throughout the month, exceeding 3°C or dropping below-12°C only one day in ten. Daily low temperatures range from -12°C to -10°C, falling below -22°C or exceeding -1°C only one day in ten.
February wasn't much different. That's not actually that exciting. Yeah, you wouldn't want to stand outside in your birthday suit, but it's not exactly Arctic conditions. Given that the guy had a sleeping bag, we can assume that he also had some sensible clothes too. Pretty good preparation, I'd say.


What's immediately apparent about a car, is that it's already wind and waterproof, which is nice. Something else that's useful about a car, is that's it's insulated from the ground rather well, it being not only raised off the ground, but held up by inflated rubber tyres. So far, so good.

My former colleague was quoted in the Telegraph as saying that trying to survive in a car was going to be gruelling, since it was made of metal. If this was an isolated fact, it would be true, since a metal shelter is highly conductive of heat and quickly evens out the inside and outside temperatures, basically, making the inside temperature fall to that of the surrounding environment. I imagine the quote was taken from a quick phone call, which is the normal way the press gets a sound bite for a story.

It turns out, if you have a look at the press photos, that there was a good 50cm of snow on the top of the car and given that he was dug out, we can assume that was covering the whole car. Snow is about 80%, which makes it a great thermal insulator. Snow has a thermal conductivity (k) of around 0.16 W/m K, which is better than brick (0.18), but not quite good as wood (about 0.12) but it's about 7 times better than glass (1.1), 250 times that of steel (55) and 1400 times better than Aluminium (237). We can assume the car had some form of meagre insulation, but we all know how quickly a car gets chilly after you've stopped blowing warm air into it.

Heat transfer is inversely proportional to thickness of material, that is to say that twice the thickness of material yields half the heat transfer and hence half the heat loss over the same period of time. Standard  maximum roof insulation is around 270mm thick, which is around half the thickness of our snow. The materials vary, but it has a conductivity of around 0.04, which if four times better than snow. That makes good roof insulation only twice as good as the snow. So, that's not all bad either.

Other than the igloo and snow hole, another example of snow insulation is that of Uruguayan Air Force Flight 571 which famously crashed in the Andes and became the subject of a book and the film Alive. Other than the well publicised cannibalism, an avalanche covered the fuselage of the plane, killing nine, but arguably aiding the survival of the remainder.

So, what's heating up the air in the car? Well, as far as I can tell, there was only one heat source available, and that was our guy. We humans emit energy at a rate of about 100 Watts, normally, which is why a party in a small room always get a bit warm. A cheap bathroom heater is about 400W and a car is a rather a lot smaller than even my tiny bathroom. As the air in the now insulated car heats up, we cool down more slowly, so burn less calories keeping warm, unlike standing outside, where we just keep loosing heat to the largely constant temperature air and ground. 

All in all, the snow covered car is not a bad shelter at all.


Our hapless 'igloo man' was next to a wood. I still don't think he was stuck in it, so I'm going to assume he could have got out. Now let me think ... I'm cold and next to a wood. I know, I'll light a fire. Bit a no brainer. 

"But what if he didn't have anything to light a fire with?" you may ask. Well, other than the quite difficult "rubbing two sticks together" methods, he had a car, and there are loads of ways of lighting a fire with bits of car. More realistically, however, someone who travels out to photograph Elk (as it seems he was) in those conditions, should be carrying something to light fires with. If not, then frankly, get out of my gene pool. That's basic preparation.

Sat by a fire by day, sleep in the car by night. That the most efficient way of keeping warm if you don't have the skills to keep a fire going all night.


Our chap was obviously remote and said to be about 1km from a road. This road was described as "main" and there were reportedly hundreds of mapped snowmobile tracks. I don't really understand how he could not have signalled for help or gotten to the road. Either he didn't bother, or he didn't want to get rescued, or he wasn't there for long at all. Hmmm.

Sensible solutions for someone wanting to get noticed from an off road position are signs and smoke signals. That's a blog post by itself, but he obviously missed a trick there.


So, snow, that's water right? Well yes, but it's cold. This chap was said to have survived by "eating snow and ice". Good old Daily Mail, but even the Telegraph alluded to the same. More likely, he would have eaten melted snow, see above for methods of melting. 

What's wrong with eating snow? Well, consuming snow directly means that you have use energy to melt it. Even if we use body heat to melt it in advance, we're still using our own energy, albeit not from the core directly. Even if we let the nice warm air in our car warm it up, we're still taking heat from the air we heated up ourself which we'll then have to heat up all over again we have to find another way.

I'm just going to assume the car wouldn't start, because that would be a sensible way of melting snow, even if you were trapped in the car. Would also keep you nice and warm for a bit. I reckon even a little Fiesta would idle for 30 hours or so on a half tank.


He had a bit of food, but it would have run out. Snow doesn't have any nutritional value, nor does any part of a regular car. So, let's play along with the whole "trapped in the car" lark. What's going to happen here? Well, first we'll consume the sugars stored in muscles and the liver, then we're going to burn lean muscle and fats. The rule of thumb is that we can last about month without any food and make a complete recovery. There are a few contributing factors to this, largely environmental, but also some biological. 

So how did he last that long? Well, I'm going to assume that he had a bit of food kicking around, he kept as warm as possible, he had a little more fat than the average guy and was just one of those people who last longer. 

He was reportedly malnourished, which you'd expect. There is also a possibility that's he's had permanent internal damage, but at least he's alive.


Some sources suggested he went into a state akin to hibernation. Really? Come on!


This section is left for an exercise for the reader.

All in all, I don't buy it. It seems to be that the chap did not make the effort to try to survive, just curled up and waited to die. Maybe there was something more psychological going on. Maybe he wasn't really there for two months. Maybe he wasn't really trapped in the car. Who knows. It was interesting exploring the possibilities though.

Give some thought to the preparation you might now make, if you risked ending up in the same situation and the actions you might take to get yourself out of the situation in a more timely fashion.

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