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29

Dehydration will very quickly reduce your ability to undertake the activities required to survive and so finding and conserving water should be a very high priority in any survival situation. Clearly there are potential dangers associated with drinking contaminated water but these need to be weighed against the dangers of dehydration. As with most survival ...


25

How much sea water can I safely drink? = None If you drink sea water, how much fresh water do you need to drink to off set the sea water you drank? = 2.8 units of distilled water per 1 unit of sea water (to neutralize without adding hydration) The "scientific" answer to this question involves a lot of complex math, human physiology and significant ...


24

Generally speaking, no. Arguably you should never go for out for any kind of extended exhausting activity without ensuring proper hydration, i.e. packing enough fluids at least for your immediate needs. The life straw will allow you to purify water sources you find up to a certain degree, but some concerns remain: You first need to actually find water ...


19

If it is clean, fresh snow, it is safe to drink. This is basically drinking rain water. It hasn't had time to pick up pollutants when it is newly fallen. I live in New England, and kids do this all the time. You get taught early to only do this with white snow. Make sure that the snow is actually clean: the longer it sits, and the more urbanized an area is, ...


17

It depends very much on the specific geography. But the idea of "whirlpools" that suck down people or entire ships, never to be seen again (which I suspect is what fascinates you) is largely a myth. The dangers aren't any different (and typically much smaller) than those posed by whitewater rapids in rivers. Specific dangers are: Being knocked against ...


16

The question doesn't state what geographical area it's about, and it really isn't possible to give an answer that covers everything. In this answer, I'm only going to deal with pristine backcountry areas in North America, such as the Sierra. In order to interpret the scientific evidence properly, it's necessary to understand some scientific background about ...


12

Pee on it. To keep the water drinkable, you'd want to have the liquids separated but still have good thermal transfer between them. A well equipped traveller will pick his/her thermos bottle and a condom, pee in the condom (ladies would probably do it the other way around), tie the condom and put in the bottle, fill the rest with snow, cap, wait and drink. ...


12

The best way to melt snow is to put it in a bottle inside your jacket under your mid layers while you're on the move and let your body heat melt it. Do not place it against the skin, leave a layer or two between you and the bottle. It's advisable to always leave your bottle in your jacket in subzero temperatures, it can freeze if left in your bag. Melting ...


11

From a water purity point of view the same rules apply for drinking water. What is important though is the temperature. If you drink large amounts of snow at a low temperature (i.e. you don't heat it adequately and just drink it as it melts in your hand) then you may need to be careful. Basically if the temperature is low enough and you're ingesting large ...


10

Most likely a Caddisfly. They make homes of twigs and stones. CADDISFLY: The caddisfly lives only a short time as an adult but may spend several years as a larva. Many larvae can do something few aquatic insects can – they build their own shelter. Different kinds of caddisflies build different types of homes. Some species build homes of leaves ...


9

This can be calculated using a property called cryoscopic constant Kf which links the concentration of a solved substance to the freezing point depression Td: Td = m * Kf where m is the molality which is the amount of mols of solved substance per kg of solvent (here water). For water Kf is 1.86K*kg/mol and the molar mass of sugar (sucrose) is 342g/mol. So ...


8

It is normal to a certain degree that wet leather, after drying, is a bit stiffer than before. The effects will generally be worse the longer your leather was in contact with water if the water was hot/warm the faster the leather dries (so don't dry over a heater!) Normally the stiffness should go away soon if the items are worn/used: after a short ...


8

I'm going to chime in on a more practical answer. The question is not "What is the scientific case for Giardia". The question is "Why are people so scared of it?" "Or why is everyone so scared of it now, when no one seemed to care before?" Or in other words, we're not talking about how dangerous Giardia is, but rather why people are worried; specifically ...


7

Why are People so Worried About Giardia? Because giardia is commonly found in backcountry water and it is known to make some people very sick. The EPA says [giardia] "Cysts have been found all months of the year in surface waters from the Arctic to the tropics in even the most pristine of surface waters." [a] Or why is everyone so scared of it now, ...


7

As already explained in the other questions, the primary concern is possible contamination. For fresh snow and far from civilization this is very easy to identify: White is good: yellow, brown, ... not so :) Close to roads/industry there might be a non-visible contamination but unlikely to be harmful for occasional consumption (at least in countries with ...


7

Dehydration will kill you before Giardia or cholera does. So, I'd first take a measure of where I am, do I absolutely need to drink the water is question, or is there any other better (safer, need not be testier) alternative to eat/drink. If I am in a desert-like situation, and I've found this water after a long long time, and I am sure its not potable, I'd ...


6

Physically there are two ways for you to heat up the snow: by heat conduction and by heat radiation. Conduction means you place it somewhere close to your body. It does not matter whether this is directly in your mouth or on your belly, you will lose the same amount of energy. The only option to heat it up without losing additional energy is by radiation, i....


6

When I'm winter camping I always leave my water in my pot over night, so all I have to do in the morning is turn the stove on and let the ice melt. If I want water for later, I'll typically boil it, then leave it in a good thermos, which will keep it liquid at -15°C for a good 24hrs. Though not very practical, your idea with the bucket will work, just keep ...


6

Yes, you can survive it... if you've got the skills. Not many years ago I watched a film at a mountain film festival, and it was about the first guys to ever kayak the Congo River. They weren't only the first people to kayak the river, they were also the first people to navigate it-and survive. Here's a clip from National Geographic: https://www.youtube....


6

It's pretty easy to keep your water from freezing without adding anything to it, actually. If you keep it under your shell, your body heat will keep it from freezing. If you bury it under a foot or so of snow, it will stay liquid overnight (although you may get a little ice around the edges). If you boil it and put your hot water bottle in your sleeping bag, ...


6

Lets say you planned well all your hikes and you know you will have constant availability of water all along the route then you could rely only on the Lifestraw. That said even for the best planned hike you can find that a seasonal source is not available in that particular moment or that some sources you counted on might have been contaminated by chemicals ...


5

I agree with fgysin's answer (no - water is very important - even with that equipment, you still need to find water, avoid chemical pollution, and access larger quantities of water for camp chores). I also want to add: Redundancy. "Two is one and one is none" sounds silly until something breaks or is lost, and then you realize where that phrase comes from. ...


5

Such packets are included in MREs (Meals, Ready-to-Eat) and are referred to as "flameless ration heaters". The packets contain finely powdered magnesium metal, alloyed with a small amount of iron, and table salt. Adding a small amount of water results in a salt-water electrolyte fluid that allows the magnesium and iron to rapidly react and generate heat. ...


4

Some excellent research-based answers here, so I'll focus on the practical implications. First, and most importantly: Most intestinal infections in the backcountry aren't caused by bad water - the main danger is poor personal hygiene in a setting where many allow standards to slip. So be scrupulous yourself, and be wary of sharing food that ...


4

There are two natural options; none of them is quite pleasant. Alcohol Per Wikipedia, 8.5 vol% of ethanol make the freezing point drop to -3C (26.6F) (more values at at Wikipedia, also a diagram is available below). Most of the ethanol will be evaporized during cooking, so it's not that much an issue; also 14 vol% is only 6.8 wt%, so the added weight is ...


4

How many percentage does the bacteria in the water die if it is boiled? 100%. More info here: How long does water need to be boiled for to kill all bacteria / viruses? How clean is it after boiling? Is it drinkable? It will still have any dirt, etc., but that isn't necessarily bad for you. Boiling will not get rid of chemical contaminants such as ...


3

Look at the surrounding terrain and think what water would do when it rains. No place is perfectly flat for very long, so suface water will flow away from some place and gather in others. Someplace dry with little vegetation will usually have obvious channels that water made when it did rain. Whether you can see these channels directly or have to imagine ...


3

Very simply: if you eat snow, all the energy that would be melt the snow is energy currently in your body. Lots of heat loss direct from your body. If you put snow in an outer layer of your clothes, then much of the energy that would melt the snow is energy that was in the process of escaping to the outside air. Effectively the snow is capturing some of ...


3

Propylene glycol is allowed in alcoholic beverages up to 5%, and this would get you to about 29°F. You could probably throw in a little sugar, salt and good old ethanol to kick it down further. Really, nearly any solute will push down the freezing point. Maybe some salty chicken bullion, plus alcohol just to keep it from rotting. This is starting to sound ...


3

When I have frozen water bottles (usually plastic Nalgene bottles), I melt them by putting them in a pot of hot water. It doesn't take too long to melt the ice to the point you can get it out of the wide-mouth bottle. Then you can just dump the ice into the hot water. (As you get more water in the pot, make sure to ladle it back into bottles so the pot doesn'...



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