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Comment by fifilura | Hacker News Reader

There is also an extreme accident in Sweden where a couple of kids in a canoe survived (incidentially with Norwegian emergency care).

One of them found with his face under the water at 14C body temperature surviving cardiac arrest for 6 hours.

The extreme low body temperatures seems to be able to allow for surviving under extreme conditions, even without breathing for several hours.

(a bit too fancy) article in swedish. https://mirakletiannsjon.story.aftonbladet.se/

(google translate to english "Canadian" is a special type of canoe) https://mirakletiannsjon-story-aftonbladet-se.translate.goog...

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Bit of relevant trivia - in a number of languages other than English, "canoe" means both the style of boat we call a canoe in English and the thing we call a kayak. To distinguish the two, the one we call simply a "canoe" is called in those languages a "Canadian canoe" or "Canadian" for short.

My father is Swedish and used to have a Canadian canoe. He would refer to the canoe by its name most of the time but sometimes he and my grandfather would refer to it as “kanadensaren” (“the Canadian” in Swedish), and I never knew why until now. Thank you!

This is also broadly true in Ireland, (and I presume the UK). Among non-canoeists, 'canoe' can refer to a canoe or kayak, and people refer to "Canadian canoes" when they want to specify an open legged canoe.

(Although sit on top kayaks are usually called as such, confusingly).

I've heard of a saying in the medical community for cases like this - you're not dead until you're warm and dead.

> ...even without breathing for several hours.

Isn't brain damage inevitable after just a few minutes?

This is the point.

No it is not if you combine it with low body temperature. It is pretty amazing when you read about it.

I think also some surgeons used this method, icing people before surgery. Not sure it is used anymore though since it may be a bit difficult to control.

https://en.wikipedia.org/wiki/Deep_hypothermic_circulatory_a...

(IIRC this kid suffered some brain damage though, but not severe enough to stopping him to continue going to school)

Protective hypothermia is still used in brain and heart surgery, or with certain types of injuries. It isn't as extreme as the method that the Wikipedia article is about, though. Protective hypothermia only drops body temperatures by a few degrees F.

>only drops body temperatures by a few degrees F

This is the most amazing thing ever because it may point to a metabolic cause instead of a physical one, like a phase change or w/e (I mean, metabolism is physics in the end but you get the point).

And if it turns out to be metabolic, drugs could be made to induce it, in principle.

Not if the brain is cool enough, but don't try this at home.

IIRC the trick is to restore oxygenation and circulation before restoring the temperature level.

Metabolic processes are dependent on temperature.

Think of yeast cells. They barely survive at 10 °C, but they do get along in water and sugar, slowly. If you bring them up to their ideal temperature with a lot of food, they go into explosive growth and the solution starts aggressively bubbling. It's orders of magnitude more metabolic activity when it's warm. If you cool human cells down their metabolism and oxygen demands slow down in the same way.

(Not coincidentally, yeast's happy temperature is not too different from normal human body temperature. A lot of biochemical processes go their fastest around ~35 °C or so without the involved molecules breaking down, and the mammalian trick was to keep all our cells at a near-ideal point all the time. We're aggressively bubbling solutions of CO2 all the time, normally.)

In the end it’s no different from preserving groceries by putting them into the fridge. Typically chemical reactions happen slower in lower temperatures, often exponentially slower. Damage can only occur at a rate constrained by chemistry.

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