Go back and read my response: The answer is all day, every day, for weeks or months on end. As long as you are active, well fed, rested and hydrated, you can basically go all winter. You can be comfortable.
The danger point comes when those points are not maintained.
The situation is a little different near the ocean, as you have to stay dry. For work we would keep several sets of gloves and boot liners and trade them out as they moistened from sweat. We had spare clothes too, just in case.
It really comes down to food and rest. If you dont have enough energy, your body cannot maintain its core temperature, and you will get hypothermia.
I’m going to say -45 celsius and below as the point where your standard gear that you can buy an any outdoor trekking shop won’t do and you need specialized gear.
-40 Celsius is the coldest ever recorded at Anchorage, fits what people say above. Below that you get serious problems with any exposed skin, any amount of air breathed in, even very experienced and well equipped teams report injuries and fatalities when temperatures go much below -40 C. Read the preparations for the Ranulph Fiennes Winter South Pole trek attempt.
-60 celsius is the average winter temperature at the south pole, -80 celsius is the lowest recorded anywhere (at Vostok). So you can’t get really very much colder on the planet.
Note that in this kind of weather, you wouldn’t really do that. Places that far away you would drive to get to (automobile, snowmobile, dogsled, etc.) – you wouldn’t walk. Most of the communities are small enough that you can walk anywhere in town in less than a half hour. To walk that long, you’d have to be walking out in the open, unpopulated country – that’s not a smart thing to do.
The question was what’s the lowest temperature that one can be safely exposed to for at least half an hour under the given circumstances. How is “all day” an answer to that?
Now that’s just the kind of answer I was looking for. So you say -45 C is the minimum practical limit for normal gear. Let me ask about this story then. The guy walks for hours in -75 F weather. Granted he did end up dying but only when he fell in water. Was he just lucky up to that point, is the story unrealistic, or what? What do you make of it?
Well okay, let’s say he is walking in open country like in the above story but ignore the danger of falling in water.
Well in the story it’s claimed " The old-timer had been very serious in laying down the law that no man must travel alone in the Klondike after fifty below".. which is approx -45 celsius. Which is the limit I claimed you would need extraordinary gear and precautions.
Anything under 20 below F you don’t really want any skin exposed no matter what the wind speed. So it doesn’t have much impact on the coldest temps humans can tolerate with the proper clothing.
It is an answer in the sense that there is realistically no where on the surface of earth where it is so cold that you couldnt endure 30 minutes dressed to your specifications.
You’ll note that I specified that we changed our clothes at -40. If I could endure -40 in a t-shirt and jeans for a minute (remove gloves/mask/snow suit, take off sweaty hooded shirt, put new shirt on, snow suit, new mask, new gloves), then you could endure -80 for 30 minutes dressed as I was.
You mentioned comfort. I mentioned sweating at -40. Your gloves and boots eventually become saturated and your body cant keep that moisture warm. So your gloves start to freeze and pretty soon you have ice very close to your skin.
In my case I was doing dexterous work handing very cold objects. My hands got cold. If I had just been walking, that could be staved off pretty much indefinitely.
The purpose of clothing -for any season- is to regulate your energy consumption, so that your bodies mechanisms can maintain you at a optimal(and hopefully comfortable) temperature. It is when that consumption is too high that you feel cold.
Case in point: How long can you comfortably endure a cold rainy day while naked? Depends on what you are doing. When will it kill you? When you starve to death.
I have some data points for you:
Winter joggers. I’m sure someone will chip in that its actually quite nice to run when its just below freezing. Other than slippery ice, you can be quite comfortable. They dress with mobility in mind. Activity keeps them warm.
Dog sledders: We dressed about equivalent to these race officials at 2:00 minutes. http://youtu.be/UUyXKAKCpkE?t=2m. They might have endured hours of that weather. Heh. Those dogs sure were anxious to start running again.
Mountain climbers: They camp on Everest overnight in little tents, making their final push at dawn. Their little heaters dont warm them that much. They do have pretty fancy clothes, but you cannot wear a survival suit and climb mountains.
How long do you think some of those people have stand, dressed like that, waiting their turn? Well, if you have 200 plungers, and they each stay in 5 seconds, that is 500 seconds or 8.3 minutes(two people at a time), plus their run to the pool, plus the time of the briefing(a minute?), plus any complications like someone needing help getting out.
Its conceivable that someone could end up standing there in an bikini for 10 minutes or more.
Cold weather doesnt cause immediate medical distress. Even hypothermia doesnt kill you in 30 minutes.
Sir Ranulph Fiennes is going to try to cross the Antarctic continent on foot during the next southern winter, apparently. Temperatures during the trip are expected to consistently get down to around -60F.
I’ve read some of his books, and I think the guy is an absolute beast, but he’s 68 years old now and I highly doubt that he’ll succeed, even though he won’t actually be manhauling his own supplies this time.
Apparently he and one other guy will only have to pull behind their skis a radar unit designed to detect upcoming crevasses. All of their tents and fuel, food, etc will be pulled by motorised vehicles that will be following them. I still don’t think that it will end well.
Mind you, if I was a sadistic mad scientist I’d like to make a few clones of Henry “Birdie” Bowers from Scott’s party a century ago, and see what a bunch of them could achieve in extremely cold conditions. During the six week long “Worst Journey in the World”, where he and two others gathered Emperor penguin eggs during the Antarctic winter, he didn’t even have any problems sleeping when it was -60F. When Scott’s party was approaching the South Pole the five of them only had four pairs of skis, so Bowers just went on foot.
Read up on him. That guy was an absolute f***ing freak of nature.
But I’ll one up you, twice. Read up on “The mad trapper of Rat River”. Find the book(its a short but good read) if you can.
Harder to find is stuff on Jerry Potts. Jerry Potts - Wikipedia The wikipedia reference doesnt discuss him unerringly finding a destination in a snow storm.
A very informative post, but just to be sure, you’re saying that even at the South Pole when it’s -120 F, one could dress up in the type of clothing you’d expect someone at the South Pole to have, go for at least a 30 minute walk around the base (assuming the weather is otherwise nice), and return with no health problems? That’s very surprising to me if so.
Why is that so surprising? The folk who spend the winter at the South Pole, and even more so Vostok, are wearing appropriate clothing outside when they have to go out. They’d be dead if they didn’t. Why is your 30 minute outside exposure significant? Indeed, what do you think is nice weather on a high plateau close to the southern pole?
It’s hardly ever close to -120F in Antarctica. That’s record cold. It’s usually much warmer even in the dead of winter.
I grew up in Fairbanks Alaska, where we got to 60 below a couple of times every winter.
It is perfectly safe to go outside at 60 below with normal cold weather clothing for an hour or two. What makes it dangerous is if you get damp, or disoriented, or tired or hungry. If you are hiking there is absolutely no margin for error, a simple mistake can cost you your life. There are two dangers, frostbite and hypothermia. Ironically, because you are wearing warm clothes hypothermia isn’t the biggest danger. Much more likely is frostbite, where the tissue of your extremities literally freezes. Your core temperatures can be fine but your fingers, toes, ears and nose can be literally frozen.
You can lose fingers and toes and ears to frostbite in a very short time if you aren’t dressed appropriately. But since the OP specified that the test subject could wear appropriate “normal” cold weather gear, that’s not a danger for the short times he’s talking about. People tend to spend an absolute minimum amount of time outdoors when it gets colder than 40 below. That’s damn cold and not any fun, and 60 below seems three times colder.
At 60 below it starts to feel like you’re on an alien planet. Sounds are distorted, the air is absolutely still, ice fog as thick as peanut butter, and you can feel the cold punching you in the face as you walk. Also, cars left outside won’t start even if they’re plugged in, metal and plastic items become extremely brittle. Nothing more embarrassing than going to open your car door and having the handle snap off in your hand.
Some of the indigenous peoples of the southern end of South America lived in the cold in little to no clothing. They were nomadic and didn’t really build shelters.
I’m from Texas. It’s strange to even think that it has hit -120 anywhere on Earth. I figured they just didn’t go outside when it hit such extreme temperatures.
And I do know that -120 is (almost) the record temperature, not the winter average. Still, if you stay at South Pole or Vostok Station through the winter, you’re going to see temperatures close to that at some point.
