Hot answers tagged

42

The calories to melt even frozen water are pretty small, and the water gained is certainly greater than that used to aid the use of those calories. http://en.wikipedia.org/wiki/Calorie So 1 calorie = 1 degree celcius (roughly with minor variation). Okay easy. Except it takes 30 times that to melt it initially. Screw snow, let's figure on ice cubes. 1 ...


39

The conclusion is not correct. Some bacteria produce toxins which are not destroyed by heat, for example Staphylococcus. See this link for more information. Note that this is not strictly an outdoors issue. Even at home, you should not keep fresh meat in your fridge too long before cooking it, as it gives time for bacteria to produce toxins. The ...


38

Obviously, what you decide to pack depends on your trip and the environment, but these are the staples I always bring along: Navigation: You always need to be able to figure out where you are and which way you need to head to get out. In my opinion, a map without topography isn't a map (unless you're on very flat land). GPS with extra batteries Local ...


38

If you look at the current time, and imagine yourself in the center a big analog watch, just place your shadow on the location of the hour's hand. Then imagine the location of the 12 o'clock hand, and exactly in the middle of the angle between those two hands is the north. Be sure to ignore daylight saving time (As the time your hand watch is showing during ...


36

All the advice I've seen emphasises melting snow before consuming to avoid lowering your core body temperature (rather than, specifically, risking dehydration). If possible, melt the snow using a stove, or alternatively, pack the snow into a waterproof container and keep it in a pocket or your sleeping bag until it melts. News stories such as this one, ...


32

There are different types of being stranded; there's "lost the trail an hour in" stranded, "lost the trail twenty miles in" stranded, and "broke a leg" stranded, just to name a few. Considering your question Multi-day Hiking -- Therefore I assume you have standard hiking gear and are not asking for that. Also assuming that you're not going to be nearby ...


32

Assuming you don't have a genitourinary tract infection, fresh urine should be sterile, the problem is that it is a waste product which, apart from making it not taste very nice, means that consuming it will increase the concentration of waste in your body which will require an increased volume of water to absorb and subsequently excrete, resulting in you ...


30

The EPA recommends boiling for one minute for most people, and three minutes for anyone above one mile in elevation. reference - http://water.epa.gov/drink/emerprep/emergencydisinfection.cfm#method That is what I have always done when backpacking. I don't boil for 10-20 minutes because it will kill my fuel supply and waste too much of the water. If I were ...


30

First, you won't need to make this observation if you routinely drink when you stop to rest, and if you eat something at least slightly salty whenever you snack (if your snacks include jerky or salted nuts you're more than covered.) Second, pay attention to your thirst. Many of us ignore our bodies for hours at a time - postponing bodily functions during a ...


29

This article (*) gives a good summary of the efficiency of boiling as a method for making water safe for consumption. In particular, Table 2 provides a summary of the temperature and time required to kill various micro-organisms. A distinction should be drawn between killing all pathogens and making water safe to drink. Sterilisation of water (killing all ...


28

The correct answer is to put your avalung mouthpiece in your mouth and inflate your airbag. If you don't have either of those things, then you are NOT properly equipped to be in avalanche terrain. If you get caught in an avalanche when you are not properly equipped, then the best you can do is 'swim' like crazy to try and keep yourself afloat, and then ...


28

Here is an article that quantifies the heat loss effects of cotton, polyester and polypropylene: Rossi et al., Dry and Wet Heat Transfer Through Clothing Dependent on the Clothing Properties Under Cold Conditions, International Journal of Occupational Safety and Ergonomics (JOSE) 2008, Vol. 14, No. 1, 69–76. Experimental Summary Here is a rough summary ...


27

I personally had a similar sort of a question when I first went through similar kind of stats about these mountains. Getting introduced with these stats is different than totally understanding the mountain and the pandora box it opens. For getting acquainted with the reasons for so many failed attempts, one needs to read tactical data and expedition reports. ...


26

There are many, many ways to make a fire. Some require more skill, while others depend on carefully prepared equipment. The closest thing to "rubbing two sticks together" is the hand-drill. You will need a fireboard (a small cedar board is good) and a thin, straight stick. A knife is good, too. This takes a lot of practice. Hand callouses help. YouTube has ...


26

Copy and paste from the answer here: http://skeptics.stackexchange.com/questions/1540/is-it-a-good-idea-to-drink-your-own-urine-in-a-survival-situation Summary: You can do it, as a last resort, but it's dicey. The US Army doesn't think it's a good idea and lists it on its "Do NOT drink" list, stating in its Field Manual that it "contains harmful body ...


26

Hot soup mostly, it does depend on the individual diets of the climbers, not everybody eats the same thing, but most carry hot soup with them. Despite the massive amounts of energy needed to summit Everest, the truth is most climbers don't eat much on summit day, and that's simply because they don't have an appetite due to the high elevation. Many climbers ...


25

If there's a stick around and enough sunlight, I've found the stick method surprisingly accurate: Find a straight stick, around 2 feet long (length isn't that important) and plant it straight in the ground. Mark the end of the stick's shadow, perhaps with another short stick. Wait for about 15 minutes then repeat step 2. Draw a line between the two ends ...


25

It is likely caused by iron in the pump or pipes. According to the Illinois Department of Public Health: Iron is mainly present in water in two forms: either the soluble ferrous iron or the insoluble ferric iron. Water containing ferrous iron is clear and colorless because the iron is completely dissolved. When exposed to air in the pressure tank or ...


24

There seems to be a fixation with North in navigation. Step back to the basic purpose, why do we navigate? We navigate to get to somewhere or to find our way back. Knowing north is just one method of doing such. So predicating navigation on knowing which way is north is unnecessary. North isn't the goal, it's a reference for finding what you really ...


22

Dehydration occurs when there is more water going out or being used than is going in. Additionally, if you're drinking too fast (more than a litre an hour for an average adult male), you're not absorbing the water and so it doesn't count as going in. Confusingly, dehydration can also be classified loss of water, loss of electrolytes or loss of both. To add ...


21

Ah, why wasn't this question already asked here! As Food and Hydration: If you are trapped on an Island (Refer: Castaway) probably Coconut Water can be only major source of potable water for you. As a bonus though, it contains a lot of nutrients, a great source of glucose and Potassium. Coconut meat, the white substance is totally eatable, contains Vitamin ...


20

The best advice is not to unless you are very, very sure. Having said that, and just for fun, assuming you are in a chronic survival situation with no choice, this article describes how to test if a plant is edible.


20

I like the native american fish trap (fishing weir). It's relatively easy to build if you have the right access to a stream. The basic idea behind this trap is to create a funnel that the fish follow into a trap that they cannot easily get out of. To build it, you simple stake off an area with small branches pushed down into the mud. The water must be ...


20

First of all the odds that you startle a bear in this way are quite low. There is a good chance that it would have heard or smelled you before you get that close. That said, if you encounter a bear in the wilderness, your reaction depends on how the bear is acting. In most cases, the bear will be defensive. In this case you should stay calm, talk calmly ...


20

For hunting bears you have to check with your local rangers for hunting season, permits and so on. Self-defense is self-defense if your mental state does not allow you to think and you feel killing is the only way out than it the only way out. BUT Bear Defense Spray is more effective and easier to obtain than .45 Also Noise will scare them off. So if ...


20

TL;DR - First try to identify if the wire is supposed to carry electricity (insulators on posts/wire goes to an electrical box/posted warning signs/ect...). There's really not much you can do to check the wire for current without a device aside from listening to it, touching it (potentially dangerous), or throwing something onto it that might react to a ...


20

Yes, there have been studies on how much various fabrics insulate when wet and dry. I remember Dr Murray Hamlet mentioning these statistics in one of his lectures on outdoor survival in the cold. It's been a long time, but I think cotton looses something like 80% of its insulating properties when wet. I may be off on the exact number, but I definitely ...


19

With fog, the only thing you're losing is extended visibility. This shouldn't throw off your plan too much, unless you were navigating by watching far away landmarks. If you were on a trail, stay on it. There's no need to wander around. If you can't see anything and traveling is becoming dangerous or you're not sure where you're going, then stop and wait ...


19

Urine is normally sterile (barring urinary tract infections) - so, from bacteriological stance, fresh urine isn't going to hurt. The problem is - urine is a waste product, and so is full of stuff that your body wants to be rid of. Worse, as you get more dehydrated, your body produces more concentrated urine. That said - as a short term measure to keep ...


19

First off, weigh up whether it's worth crossing said river. I know this question is about if you "have" to cross it, but bear in mind that falling in is a real danger and if you do, hypothermia can onset very quickly and be deadly. It depends on the situation - if we're talking about a shallow, wade-able body of water that's not much more than a stream I'd ...



Only top voted, non community-wiki answers of a minimum length are eligible