Comment by pinkmuffinere | Hacker News Reader

Comment by pinkmuffinere | Hacker News Reader

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> During their simulation of Mallory’s Everest expedition, the data showed that on summit night, the average body temperature difference between the twin in modern down and the twin in complicated layers of silk, wool, and gabardine was a staggering 1.8°C.

The human body self-regulates, and is pretty sensitive to dramatic temperature swings. So, conditioned on the fact that they both survived the adventure, we should expect their temperature differences to be relatively small. This doesn't mean the clothing is great, it means [their body] + [their clothing] is adequate.

Additionally, I'm not a doctor but 1.8 C is not small compared to normal human variation! Normal body temperature ranges between 36 and 37 C, a "high fever" starts around 39 C [0], and hypothermia is anything below 35 C [1]. The comfortable range of human temperature is 1 deg C, and the "outside of this is concerning" range is only 4 C wide. 1.8 C is quite big from that perspective.

[0] https://www.health.harvard.edu/diseases-and-conditions/treat...

[1] https://www.mayoclinic.org/diseases-conditions/hypothermia/s...

Right, the 1.8C difference is substantial in terms of human physiology and indicates a diminished level of comfort as the body fights to keep the temperature up.

I also found it funny how they mentioned that modern clothing keeps you warmer longer once you stop moving, then tried to minimize the significance of that. There's a reason "cotton kills" is a cliche. Modern fabrics, windbreaker shells, and engineered layers don't make a huge difference in warm, dry, active conditions - it's when things go sideways that they can be the difference between comfort and fatal hypothermia.

There are times when layering is not the way to go. One of them is heavy activity in extreme cold. Layers can cause moisture to freeze in bad places. Having lived in a place that often got down to -40, I was always most comfortable with a light synthetic shirt under a single winter coat. No complex layers. And waterproofing isn't needed as there isn't any water around.

I also and have gone to -46F and for me a thick wool sweater and wool felt coat makes huge difference. I can not even wear my wool sweater until it gets to -20F otherwise I will burn up :)

My record was -63f/-53c. But it isnt all that bad. There is literally no weather/wind below about -40. No snow. No wind. No clouds. Only strange stuff like ice crystals falling from a clear sku, and snow that squeeks like walking on styrofoam. -35 and windy always felt colder than -50.

Ice crystals: https://youtu.be/4yBNmoa4htE

I know someone who has three or four different thicknesses of pure lambswool jerseys for wearing while he's cycling, at different air temperatures. It never really gets all that cold down south here at 56°N and frankly I think spending ten minutes dicking about over which jumper you're wearing for optimal performance takes a lot of the fun out of it.

That said, I'm a fat 52-year-old, and I cycle in jeans and a T-shirt, and if I start to feel cold it's a sign I'm not pedalling hard enough and I should get the boot down a bit, burn some calories.

I'm still faster than many-jerseys-guy.

Does it take 10 minutes to choose? Back when I was commuting, I had different kit depending on the temperature, and it wasn't exactly hard.

>50F: Summer gear, and not much of it. I run hot, and there's no need to make it worse.

>20F: Add a thick sweatshirt and gloves

>0F: Add wool socks, long pants and a wool underlayer, a windproof outer shell, glasses, a hat, a thicker windproof layer over my gloves, and sometimes a scarf depending on how short I'd cut my beard.

>-20F: Similar, but with some extra layers over my core, and the scarf is mandatory.

>-40: Similar, more layers.

<-40: I know my limits. I've nearly gotten in serious trouble before when it's too cold out and I didn't plan for extra wind and a cold pocket near the river or having to walk because of a poorly maintained road or whatever. My gear wasn't especially high-tech, and I just called work and emailed my professors to let them know I wasn't going to make it.

Wind would have me reaching for wind breaking and insulation at higher temperatures.

It wasn't a 10-minute process by any means though. I'd pull out my phone in the wee hours of morning, see that it was X temperature on the homescreen, and plan accordingly. If he's just selecting between a few jerseys that should be even easier, right?

-20 and -40? You're harder than me, I move indoors onto the turbo when it gets much below 28*F.

I didn't have a lot of choice. I was pretty broke and also couldn't afford to skip 2 months of work or school. Nowadays I'm a bit more careful with my time.

If you start doing longer rides you learn there are general temperature ranges and kit that's fine to commute in or ride an hour in traffic with a rucksack is very different from the kit you want on a 6 hour ride in the countryside. I generally have kit for 0-10, 10-15, 15-22, 22+°C. My 0-10 jersey will boil me alive after an hour cycling in 13°C but likewise my 10-15°C will risk hypothermia in 8°C. There's only so much layering you can do with cycling kit before it starts becoming restrictive.

At one point I was stationed at a military base in the north which got to -40, even -50 somewhat regularly in the winter. Part of the orders for extreme cold was "no bicycles". Too many cardio nuts were seen riding in inadequate clothing, especially lack of proper boots. The worry wasn't them getting cold, it was them falling.

A light jacket is all good when you are pumping out the calories, but take a fall and you are now sitting on the ground unable to move. At -40 you may have only minutes before life-altering cold injuries (lost toes). Add to that the darkness and snowbanks and you might not be found for hours... IF anyone is actually looking for you. Cellphone screen get tricky in serious cold. A person walking to work, which was still not advisable, would at least be wearing clothing warm enough to stand still in the cold.

The radio used to have public service announcements calling for people to keep blankets in their car. Not in the trunk. Within reach of the driver. Get into a wreck, trapped without heat, and that fleece blanket under your seat might save your life.

I still shiver uncontrollably when I remember winter training at Ft Drum... brr

KI or Minot?

Much further north. I was working with the canadians. I saw weather phenomena that i have seen nowhere else, from sun dogs every morning to watching the northern lights and realizing they are actually in the southern sky.

I'm curious: I do cycle in jeans and a t-shirt while in the city. Up to 45 minutes I'm perfectly fine, but if I'm on the saddle for over one hour I really start to miss the chamois. What's your experience with that?

Brooks saddle (actually very on topic in this case)

Seconded. Old-school leather saddles are pretty good for riding in street clothes. But, they do tend to require a slightly different fit - I never managed to run one with my normal saddle-bar drop - the Brookes really wanted saddle and bar at the same height and the nose of the saddle pointed up a bit. This was good for ~2 hours or so, never tried it for longer, since I had normal road bike with normal saddle for that.

Mine is on a mountain bike. Ride 3x per week, two-hour rides. Still hurts when I switch to someone else's bike/seat.

My old bike had a Brooks saddle and I gave it to someone to use with no real expectation of getting it back, and sure enough I didn't get it back. They're still using it though :-)

I wish I'd swapped out the really nice saddle for a more entry-level one though.

I didn't see more details in the article, but my guess is they were taking and averaging multiple temperature reads across the body. That is, core temp should only be within a narrow range like you say, but fingertip temp will vary much more widely.

All in all I found this to be a very strange article. If you just look at the data, I think a reasonable conclusion is that modern gear is vastly better at its function than old time Mallory gear. It's much lighter and keeps the wearer much warmer than old gear. But the whole tone of the article is about "myth busting" and how there haven't been really that many improvements in gear. I'm just looking at their charts and data and wondering what they're smoking.

A few things are lighter, but others are basically the same. Check the graph:

https://i.imgur.com/WKcLVDt.png

Across their boots, legs, and upper body, they're at 6.578 kg/14.4 lbs for the old gear and 6.373 kg/14.0 lbs for the new gear. Yes, the newer gloves and headgear are significantly lighter - 1.132 kg/2.5 lbs vs 0.463 kg/1 lbs, and I don't know what they're bundling in "accessories", but the difference is nowhere near what I would have imagined.

Also, I've got some lightweight modern gear from companies like Patagonia, Montbell, Sea 2 Summit, REI, and others, and if I could get the same performance out of waxed canvas and leather at the same weight I'd ditch those systems in a heartbeat. The nylon is finally ripstop, but it's thinner than ever and tears when you rub your shoulder on a thorny branch.

But I don't think you actually get the same performance at the same weight. You're colder and have to be more careful about stopping and getting hypothermia, but your old gear weighs the same? Then you should get more of it.

I think they're "debunking" a strawman argument that old gear was completely useless

Obviously that older gear wasn’t useless, since real people used it to climb the exact same mountains that people climb today.

It’s pretty clear from the text that they have debunked the idea that modern synthetic materials have outstripped older materials in performance. At the start of their project they expected modern gear of similar capabilities to be lighter. What they found was that modern gear’s advantage is primarily that it is simpler to use. Instead of seven carefully–chosen layers of wool and silk, you can wear a single coat. That single coat is also effective over a much larger temperature range than the older clothes.

Really this should not be all that surprising, as the expertise required to pick those layers has been condensed by engineers into the design of the coat. The modern climber no longer needs that same expertise, just money to buy the coat.

This is the same story of specialization that has powered our economic growth for centuries. You and I no longer need to know how to grow vegetables, or shoe a horse, or design a circuit. There might still be advantages to knowing how to write a sonnet or plan a battle, but for the most part we can leave these tasks to specialists who can get better results than we can. Those specialists in turn can leave other tasks to us. Everyone gets more efficient as a result.

> It’s pretty clear from the text that they have debunked the idea that modern synthetic materials have outstripped older materials in performance... That single coat is also effective over a much larger temperature range than the older clothes.

It feels like these two statements are in contradiction.

FWIW, I do a lot of hiking / backpacking / snowboarding in various conditions and "effective over a much larger temperature" is the #1 thing I shop for. If I can have 1 jacket that I wear from the time I get up in the morning until lunch, that's worth more than any other feature. I hate having to stop a hike to strip off a layer and I hate having to find a way to carry my jacket while snowboarding.

> outstripped older materials in performance

As measured in mass needed for a given amount of insulation. They expected the modern materials to achieve the same protection from cold while being lighter. That’s not what they found.

> If I can have 1 jacket that I wear from the time I get up in the morning until lunch, that's worth more than any other feature.

Yes, I suspect that many people think adaptability is even better than raw performance. After all, most of us don’t have a sherpa who can carry our jacket while we snowboard.

It was 1.8 C difference in skin temperature, not core body temperature. As you note, 1.8 C would be massive for core temp.

Wearable thermometer patches attached to each man’s head, chest, hands, feet, and legs recorded body temperature at five-minute intervals, nonstop, for the entire 10 days of the expedition.

I'll argue that, if it got down to the sharp edge of survival's knife, only the 2-degree warmer twin would come home. 2 degrees C (3 F) is palpably warmer.

That being said, if a 2-degree dip in temp would kill you, you are already praying for Ernest Shackleton's leadership.

I'd rather pray for Roald Amundsen's leadership if I wanted to actually survive.

Any theories or conclusions in the article especially with regards to science and medicine is best ignored as the article was written by an LLM.

The photographs and text within quotes are probably the only human things in there. We might go to the source of the data (the brothers instagram) for better conclusions, but for me this well is poisoned by slop.

I think both points can be true at once

"Normal body temperature", ok but these are two mountaineering nerds (not normal) so who knows.

Do you imagine that "nerds" have different bodies than "normal" people? I mean, sure, they're athletic, but they still go to human doctors, not some sort of xenobiologist veterinarians.

They may have started out the same as you or me, but the conditioning and acclimatization they’ve done over their lives certainly makes them more adapted to the activities they’re doing than the average person.

Serious question: do you really think mountaineers have a different resting core temp than "normal" human beings, as you apparently have claimed?

Not to be a stickler (ok I like being a stickler) but temperature delta, especially deltas between degrees celsius, should be given in kelvin. A 1.8K difference makes sense. A 1.8C difference would be 274.8 kelvin!

This is probably the most ridiculous comment I've read in the history of this website.

There is no difference in the amount of energy 1 degree Celsius delta and 1 degree Kelvin delta represents.

The only (and I really mean only) difference is how zero energy is defined. It is not possible to have negative energy, and that zero Celsius represents the freezing point of water is an artifact of convenience, not of absolute definition.

Also, the way Kelvin is defined necessitates that both degrees are identical. If 10 degrees Celcius defined the boiling point of water at 1 atmosphere (or whatever the actual definition is) then Kelvin would be smaller by a factor of 10. And this applies to both negative and positive K values.

Ranking, Celsius, Centigrade have the degrees. Kelvin is a base unit, absolute and no degree!

Taking differences between degrees Celsius values is absolutely fine.

Ratios are undefined because the Celsius scale has no absolute zero while the Kelvin scale has.

See: https://en.wikipedia.org/wiki/Level_of_measurement

>A 1.8C difference would be 274.8 kelvin!

Categorically and factually incorrect.

A 1.8 degree C different would be 1.8 kelvin. The two degrees have different zero points but one degree Celsius and one degree Kelvin are identical in magnitude.

Celsius is not an absolute scale, but that isn't a problem for deltas: (10C - 5C)=5C, (10K-5K)=5K. Celsius is only problematic when multiplying or dividing. 10C is not twice as hot as 5C.

> A 1.8K difference makes sense. A 1.8C difference would be 274.8 kelvin!

I think there was some insight here that went off on a bad tangent leading to a math word-problem mistake, confusing these two:

1. A difference... between [X] and [Y], which is a delta of 1.8°C

2. A difference... between [0°K] and a reading of [1.8°C], which is a delta 274.95°K.

That makes no sense. A difference between a read of 37C and 38.8C is still 1.8C.

To be a stickler, communication requires respect for your audience. The vast majority of everyone understands a 1.8 degree C delta. I would argue that very few people anywhere would understand a temperature delta given in kelvin.

How is expecting readers to not understand what a kelvin is respecting the audience?

You misread.

Most people do not understand temperature on the Kelvin scale. As such, you should not use it to communicate in a general setting such as this.

The same way expecting you understand what a Kelvin is isn't respectful to you.

Kelvin and Celsius use the same unit magnitudes. It would be a 1.8* difference either way.

"A 1.8C difference" expands as "A difference of 1.8C" expands as, and here's the ambiguity, either:

"An absolute difference of 1.8C, or 274.8K, measured between A and B"

or

"A relative difference of 1.8C, or 1.8K, is added/subtracted to A/B in order to reach B/A"

I don't think the context-free variant with K will improve understanding and decrease confusability in this discussion context, but I appreciate the pointer about it in general. I'll take a lot more care around it in a future thread about space apparel!

No it doesn't. The absolute difference[1] of 1.8°C is the same as 1.8K; they have the same scale. The subtraction of values cancels out the offset.

A relative difference[2], usually given in percent change, has problems with a unit that has an offset zero like Celcius, but that isn't what anybody is using here. It's more than simple subtraction; you have to divide by the reference value.

[1] https://en.wikipedia.org/wiki/Absolute_difference#Applicatio... [2] https://en.wikipedia.org/wiki/Relative_difference

You're just confused by terminology. While 1 C is 273 K, 1 degree Celsius is 1 degree Kelvin.

See, a degree is not an absolute unit of measure like a Celsius or a Kelvin, it's a relative difference between two absolute units of measure. When discussing the difference between two separate temperature readings measured in Celsius, degrees Celsius is entirely appropriate.

Think of it like time: there is a difference between meeting at 2:00 and meeting two hours from now.

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