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jldugger 2 days ago

> 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. > “In a hundred years, you’ve gained—arguably—one degree of efficiency per 50 years,” Ross reveals.

Depending on where the baseline is, 1.8 degrees could be huge! But more importantly, heat dissapation is a non-linear function. The warmer you are relative to your environment, the more energy is lost. While Shackleton's kit forms a lower baseline, it probably makes sense to imagine how some imaginary perfect vacuum insulated sleeping bag would perform.

Aurornis 2 days ago | parent | next [-]

Is that really core body temperature?

Normal core body temperature is around 37C.

Hypothermia starts around 35C, only 2C less.

If they're actually measuring body temperature (using that swallowed pill they mention?) then 1.8C is a huge difference.

This whole article does feel like they started with a conclusion and they were going to report that conclusion regardless of what they measured or experienced. Content that claims to debunk things is hot right now.

systemsweird 2 days ago | parent | next [-]

Also the body will increase metabolic rate in the cold to maintain body temperate which is an externality they aren’t measuring. The user of the worse clothing is very likely burning more calories and still not as warm. This would mean increased fatigue and greater food weight on expeditions.

throwaway173738 2 days ago | parent [-]

Or they can move faster or carry more weight. You can warm yourself by moving or by metabolism.

IAmBroom 2 days ago | parent | next [-]

"We aren't carrying the best gear, so we'll just hurry a bit climbing Everest... and carry heavier packs of food, too."

tantalor 2 days ago | parent | prev [-]

It's mostly from metabolism, friction is negligible (<1%).

thaumasiotes 2 days ago | parent | prev [-]

> Normal core body temperature is around 37C.

Traditionally, yes.

In practice, modern people are a bit colder than that. The 37C value is old enough that it's out of date, but the reasons why aren't well understood.

margalabargala 2 days ago | parent | prev | next [-]

This whole article is kind of a straw man anyway.

Warmth of clothing isn't actually what people care about. What people care about, and what the article does not mention, is warmth per unit weight.

altairprime 2 days ago | parent | next [-]

I disagree. People also may care about the cognitive load of thermal management. As the article notes:

> the gear of the past is capable, but it has a narrower operating window. If you stop moving in Mallory’s kit at 8,000 meters, you will freeze quickly. Modern gear buys you a safety margin if you become static.

In modern terms, this means that stopping to take a photo — whether Ansel or selfie — would carry a material risk of harm in the classic gear that is addressed by modern gear. The example of a selfie is perhaps too easily dismissed unconsidered, but the cognitive load is real for casual hikers, and is a benefit to modern gear that deserves the mention it gets. If I had to choose between a cap that has perfect heat management and a cap that weighs 10g less but requires me to constantly take it off and put it on every five minutes to allow evaporation, I would choose the heavier and lower annoyance cap. Each person’s preferences and skills apply; if one seeks to minmax weight/thermal then that’s a negligible price to pay to improve — but only some truly do strive for the limit of lowest mass without regards to complexity.

There was an enviro-scifi book from the eighties that noted that a few people will pursue ‘one piece of apparel serves all functions’ skinsuit to the exclusion of all other concerns (such as natural fabrics or apparel design), at which point we would plausibly expect to see at one extreme the folks who make a discount-ultralight vented bodysuit out of FedEx envelopes. I am taking for granted that someone has tried this, because of course someone has tried this! And that starts to verge on why, in a different enviro-scifi book of that same relative era, the stillsuit existed: the lightest way to have convenient purified water in an absurd climates. Even the stillsuit as we see it described prioritizes convenience, the sip tube, over a more efficient system that doesn’t expend calories on pumping water up. That’s purely because human beings have a cognitive annoyance limit; and we do variably prioritize convenience when assessing the weight-complexity tradeoff.

throwawaytea 2 days ago | parent | next [-]

I go mushroom picking in the Oregon forest every year. The only real dangerous moment I ever had was getting soaking wet, and when the storm cleared, I stopped like a fool to eat lunch in a sunny for breezing opening. I finished lunch, and realized I was shockingly cold. Like, dangerously cold. I did jumping jacks as long as I could and then started walking uphill even though that wasn't where I wanted to go really. Weird moment.

throwaway173738 2 days ago | parent | next [-]

I didn’t wear my rain gear hiking uphill in a quarter inch per 4 hours downpour and started feeling sleepy by degrees until I caught myself looking for a place to lie down for a nap. At that point I realized I’d better turn around posthaste.

ghaff 2 days ago | parent | prev [-]

I used to lead hiking trips and being wet (and/or exposed to rain a bit above freezing is generally more dangerous than being mostly dry in colder temperatures

bryanrasmussen 2 days ago | parent | prev | next [-]

It must just be that the way the stillsuit functions is because of the limits of Herbert as a engineer and designer had been reached and he did not think or realize that there was a more efficient system than the sip tube possible.

altairprime 2 days ago | parent [-]

Dunno. I'm content analyzing the analogy as if authorial limitations did not apply; it helps fend off the entropic forces of IDIC given the necessity of using flawed examples to communicate at all.

Xfx7028 2 days ago | parent | prev [-]

What does Ansel mean?

grvbck 2 days ago | parent [-]

Most likely Ansel Adams, famous landscape photographer.

altairprime 2 days ago | parent [-]

Oops, yes, this, sorry!

stevejb 2 days ago | parent | prev | next [-]

Their bar graph showed that in almost every category except for accessories, the weights were pretty much identical.

margalabargala 2 days ago | parent [-]

"Pretty much identical"

Add up the numbers in the bar graph and you'll see that the old gear sums to two kilograms heavier than the modern gear.

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foxglacier 2 days ago | parent | prev [-]

Add body weight and the old gear sums to about three percent heavier than the modern gear. I'd say total weight matters more than gear weight alone, doesn't it?

xarope 2 days ago | parent | next [-]

I've done a lot of long hikes (200+km in the sahara, 6000+m mountains in kazakstan), and 2kg extra means a lot, like the difference between carrying extra fuel/food versus just clothing.

Anyway, you can try it yourself, wear a 2kg wax cotton jacket versus a 500gm technical jacket and see how you feel after a day's hiking.

gregoryl 2 days ago | parent | prev | next [-]

Until you take your gear off, and it's in your pack. I'd much rather lose a kg of pack weight vs. a kg of body weight.

margalabargala 2 days ago | parent | prev | next [-]

No it does not.

Two kilograms extra is gigantic.

If you have a friend who hikes or backpacks, ask them to take you along for your first time and try it out for yourself.

IAmBroom 2 days ago | parent | prev [-]

No. Weight x distance from center of mass is the real metric of burden.

Carrying your lunch on a 10-foot pole, keeping it off the ground at all times, versus slipping it into a fanny pack - or eating it and carrying it in your very center of mass.

I noticed while ultralight hiking (full kit without food, fuel, and water under 9 lbs, for multi-day excursions) that how close your backpack was to your back mattered. Unfortunately, if it was tight to your back it overheated you, so a standoff of an inch or so was essential. I considered dividing it front and back, so each was about half as "thick" (far from my body), but there isn't a lot you can carry in front of you without seriously impeding movement.

Anyway: force times distance equals work.

next_xibalba 2 days ago | parent | prev | next [-]

Isn’t there a chart showing weight by body part midway through the article?

margalabargala 2 days ago | parent [-]

Yeah, it shows the old gear is about two kilograms heavier than the new gear, which is huge.

Considering that someone carrying 2 extra kilos will also be generating more body heat etc, the focus on heat over the rest of the article is in question.

altairprime 2 days ago | parent [-]

To clarify slightly: it shows the old gear is significantly heavier in three areas: head, hands, and ‘accessories’. I think that suggests where investment in technical fabric has been most successful at improving the burden of mass in surviving extreme cold.

Fricken 2 days ago | parent [-]

Wool, down, silk and leather are still commonly used in technical apparel and compete on weight.

2 big new innovations that matter are Gore-tex and Nylon fabrics that are very durable and wind resistance for their weight.

margalabargala 2 days ago | parent [-]

Tech fabrics were a prerequisite to the widespread use of down in adventure clothing. Earlier fabrics were either too heavy, like leather, and would collapse the down and negate its insulating properties, or would get wet like cotton/linen and saturate the down.

2 days ago | parent | prev [-]
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eleveriven 2 days ago | parent | prev [-]

Small temperature difference, potentially large difference in watts