Cold Weather Considerations – Part 5, by JM

(Continued from Part 4.)


Staying hydrated when performing any strenuous activity in the winter is critical, since dehydration can cause you a whole host of problems. One big issue is that dehydration can reduce your appetite, and I’ve mentioned before how critical calories are to staying warm. However, there are a number of factors that are harder to overcome in the winter when it comes to staying hydrated:

  • Our thirst reflex tends to be reduced in the winter, which means we tend to drink less water
  • Water can be harder to obtain, process and transport
  • Water tends to freeze easily
  • Low humidity results in sweat evaporating faster
  • Cold weather typically results in more frequent urination, due to a mechanism called cold diuresis (your body squeezes water out of your blood to reduce blood pressure and make it easier to circulate)

So to begin with you need to make sure you drink plenty of water throughout the day. I try to drink at least 2 ‘glasses’ at breakfast, then at least a gallon or so during the rest of the day. You should also avoid drinking any diuretics like alcohol or herbal teas, since those will force water into your urinary system faster. Coffee is not actually a diuretic like many people believe, but you should still avoid it as mentioned earlier.

So where do you get enough water to stay hydrated in the winter? If there’s snow on the ground that’s one obvious source, although you should never put snow directly into your mouth – water is mostly air, so you’d have to consume a ton just to get a small drink, and it robs you of a lot of body heat. As a matter of fact drinking any cold water will force your body to warm it up, so keep it as warm as possible. Fresh snow on the surface should be safe to convert directly to drinking water, but you should look for discolorations or particles first to make sure it isn’t contaminated. You can melt it in a pot over a fire, which only needs to be slight warm (not hot) to melt snow, but that may take a while since you’ll need to keep adding more snow as it melts. One trick that we use sometimes is to bring a dark heavy-duty trash bag, fill it with snow and place it in the sun. In anything but the most freezing temperatures the sun will warm the bag and melt the snow faster than the outside temperature can re-freeze it. You can open up the bag and keep topping it off as the snow melts. Another option would be to place the bag near (but not too near) a fire. Either approach tends to give you a decent amount of drinkable water pretty quickly.

Ice is another potential source of water, and it has a much higher water density than snow, but you need to be more careful about its drinkability. Water can either form as icicles when melt water runs down a surface and re-freezes, or as surface ice on top of the ground, snow or bodies of water. Regardless of its source ice can potentially pick up pathogens and/or contaminants from whatever water source it came from or surface it’s been in contact with, and many dangerous pathogens can survive being frozen, so you should always filter or boil water you obtain by melting ice. If the ice comes from a water source that may be contaminated with chemicals or heavy metals you should use a filter that has a carbon element. Ice that forms on the top of snow either from freezing rain or from melting and re-freezing should be safe to drink as is.

Collecting ice can be a bit of a chore. If you can find icicles you can usually knock them down with a long stick and collect them for melting. Collecting ice from surface water can be more difficult, especially if the ice is thick. I carry a small spike tomahawk with me to harvest ice – the spike end makes short work of breaking off chunks, although thick ice will still take quite a bit of effort. This is where those disposable gloves I mentioned earlier come in handy, since grabbing chunks of ice floating in water frequently results in your gloves getting soaked.

Water filters are another potential problem in cold weather. Most work by filtering water through plastic or ceramic elements which contain holes or channels that let the water through but block contaminants, and any water remaining in the filter can freeze, expand and crack the elements, rendering them ineffective. You should always ensure you’ve removed as much water as possible from the filter before storing it and wrap it in some insulation to minimize the risk of freezing. I always store my water filter inside my shelter at night to minimize the risk of damage.

Once you have a clean source of water the next problem becomes how to store and transport it. As I mentioned earlier you should be drinking at least a gallon (about 3.8L) of water per day, and you probably don’t want to have to stop, melt and/or filter it every time you need a drink. One good solution is a hydration bladder inside your backpack – your body on one side and the stuff in your backpack should keep it fairly well insulated. They even make insulating pouches specifically for hydration bladders as well as insulated hydration carrier packs. You can also store water bottles in your pack, but depending on how cold it is they may freeze. The solution I use is a low-profile hydration system from Source Tactical. I carry it on my back under my outer layers, either by attaching some backpack straps directly to it using d-rings or by mounting it on a lightweight molle vest. It has a low enough profile that it fits comfortably under my clothing, and wearing a backpack over it on the outside is comfortable. By wearing it under my clothes I can keep it warm and always have it with me, even if I take my backpack off. The advantage to using the vest to carry it is that you can attach additional low-profile molle pouches to the front to carry other things inside your clothing that you may need to keep from freezing, like food, electronics or medicines. One other really cool feature of the Source Tactical system is the optional tube adapter, which allows you to refill it through the drinking tube without having to take it off.

Regardless of what you use to store and transport your water you should always keep it inside your shelter at night (not just inside the vestibule if your tent has one) or even inside your sleeping bag to keep it as warm as possible. This prevents it from freezing and reduces the impact to your core body temperature from drinking cold water.

Winter Movement

Moving around outdoors in the winter can present its own set of challenges, with the most obvious one being snow. Walking in a few inches of light powdered snow generally isn’t a major problem, but as the snow gets thicker and heavier walking can become extremely difficult and require a lot of energy. Snowmobiles are one answer for moving around in winter snow, but they tend to be very noisy and require gasoline and oil to operate, which you’ll need to store. You can make custom mufflers to quiet them down, or there are companies that sell electric snowmobiles that have a decent range, but you’ll obviously need some way to recharge them. If there’s a little snow (generally less than 2’, depending on the vehicle) you can most likely continue to use wheeled vehicles such as cars, trucks, motorcycles, ATVs, etc. A discussion on preparing your motor vehicle for winter is beyond the scope of this article, but there’s plenty of good information available on the web.

A more realistic scenario in a post-SHTF world is that you’ll need to use muscle power to get where you want to go. Don’t assume that just because there’s no snow on the ground that walking around won’t be any different than in warm weather. Frozen ground can be as hard as concrete, which can be hard on your joints, and that little twig that you could easily brush aside with your foot in the summer could be frozen solid to the ground and cause you to trip, so you need to pay close attention to the ground when you’re walking.

Once there’s snow on the ground things can get tougher. Even a little bit of snow can cause any surface to become slick, increasing the chance of a slip and fall. As the snow becomes thicker it can hide obstacles and tripping hazards, and walking can require you to either drag your feet through the snow or lift them high with each step, which is a lot more physically exhausting. I highly recommend a good set of walking poles if you plan on walking in snow – they’ll help you keep your balance, and you can remove the baskets and use them to probe the snow in front of you if you’re worried about possible holes or obstacles. They can also double as tarp or tent poles.

As the snow gets deeper you should consider getting some equipment that enhances movement, such as snowshoes or cross-country skis. I use snowshoes extensively for hiking in the winter, and they’re great for moving long distances with less effort. Keep in mind that snowshoes work by distributing your weight over the top of the snow to prevent you from sinking in, so you need a snowshoe that appropriate for your weight (including gear) and the snow conditions. I have an older pair of MSR Denalis with the large float tails (which MSR replaced with the Evo series), and I’ve beat the crap out of them for nearly a decade and they’re still in great condition.

If you’re looking for something lighter and easier to learn take a look at the Crescent Moon Eva series – they’re made entirely of foam and work well for beginners. I rented a pair last winter at a local ski area and they’re easy to use and very comfortable, but I’m concerned about their long-term durability. If you want something more traditional the US military magnesium-frame snowshoes are supposed to be good, but I’ve never actually tried a pair. Be careful with snowshoes that are made of flexible plastic stretched inside of an aluminum frame – there are quality versions available, but those are the types of snowshoes I’ve seen break more often than any other. You’re also going to want a decent set of poles to use with your snowshoes – make sure you get a pair that has wide baskets to keep them from sinking into the snow. Regardless of what kind of snowshoes you get, make sure you practice with them in as many different kinds of snow conditions as possible.

Cross-country skis are another option to consider for moving through snow. If conditions are right and you’re reasonably competent in using them you can cover quite a good distance on relatively flat terrain much faster than walking or snowshoeing. Note that most people learn and participate in cross-country skiing on groomed trails, which won’t exist in a post-SHTF world, so if you plan on including them as part of your preps you should make sure you practice breaking your own trails. In conditions where you’re breaking trail in snow that’s covered with a layer of ice you’ll be using your shins to break the ice, which becomes very painful very quickly, so bring something you can strap on to use as shin guards. You can also use cross-country skis to ski down hills, called telemarking, which definitely requires some training and practice to get right. Cross-country skis and boots need to be fitted your body style, show size and weight, so this is one thing you should buy at a reputable ski shop. You can usually find some good deals on ski/binding/boot packages at end of year sales.

Get a Gear Sled

If you plan on covering a long distance in the snow walking, snowshoeing or cross-country skiing you should consider a sled for your backpack and gear. I have a cheap small plastic kid’s toboggan that I bought at a dollar store years ago that I attach to the outside of my backpack with some short bungie cords. I can quickly take my pack off, set it toboggan-side down on the snow, attach it to my waist with some paracord and pull it along behind me. This improves my balance and makes moving through the snow easier in most conditions. Note that if you’re going downhill you need to avoid having the sled taking your legs out from behind, so if I’m walking or snowshoeing I move it in front. I’ve never actually found a good way to use an equipment sled going downhill with skis, so I just put the pack back on for that.

If you’re moving around outside in the winter you may eventually have to cross some frozen water. That’s one activity that scares me more than anything else, so I try to avoid it as much as possible and I’m super careful when I have to do it. The first thing most people think about when crossing ice is how thick it is, but it’s critical to understand that the ice isn’t always supporting your weight by itself – it’s usually floating on top of the water and spreads your weight over a wide area, keeping you from falling through. The rule of thumb is that 2”-3” of solid ice in contact with the surface of the water is enough to support the weight of a person, but of course the real world is never that clean and simple – variations in the structure, thickness, temperature and strength of an ice sheet can impact its load-carrying ability.

Since most of us don’t carry a drill or ice auger with us you need some way to dig down into the ice to determine its thickness; that’s where the spike on the tomahawk I mentioned earlier comes in handy. You should test an area that’s at least 20’ away from where you plan on crossing, since digging a hole may cause cracks or other weaknesses. However, there are a number of other factors you need to consider beyond thickness:

  • Black or clear ice is stronger than ice with lots of air bubbles in it (white or snow ice). Snow ice should be at least twice as thick to support the same weight.
  • Ice near shore is generally thinner earlier in the season due to the warmth from the surrounding ground, although in some cases it can actually freeze faster since it’s shallower.
  • Moving water freezes more slowly that still water
  • Areas near in-feed streams tend to freeze slower
  • Changing water levels can result in large air gaps beneath the ice, reducing its strength
  • Rapid large drops in temperature can cause ice to become brittle, reducing its strength
  • A heavy layer of snow on top of ice can insulate it, causing it to freeze slower
  • If the air temperature stays above freezing for more than 24 hour, exposed ice may lose a lot of its strength
  • If water is coming up through cracks in the ice it means the crack goes all of the way to the surface of the water below
  • Mottled and slushy (“rotten”) ice generally indicates the ice may be melting from below.
  • Loud cracks or booms from ice over moving water can indicate the ice is about to break up
  • If you hear hollow thumps when hitting the ice it means there’s air underneath and the ice isn’t supported by water
  • Ice conditions can vary widely across a body of water

How quickly water can freeze depends on a number of factors. Large bodies of water are great heat sinks and it takes a long time for their temperature to change, since freezing temperatures typically only interact with the surface. The colder water on top will sink down and be replaced by warmer water, until the entire body of water has reached a relatively stable temperature. The result is that standing water will generally take longer to freeze early in the season than later on. If the water has been frozen once and it melts due to higher temperatures for a short period of time, it will usually freeze a lot faster once temperatures dip back below freezing. The only way to be sure is to measure the thickness and check the conditions along your planned route very carefully.

If you absolutely have to cross ice there are a number of things you can do to improve you odds of making it safely:

  • Never ever cross ice alone. There should be at least two people, with everyone tied together with at least 20’ of rope between them.
  • Spread the load. Wear snowshoes or cross-country skis and pull your backpack along behind you to reduce the weight on any given part of the ice. Pulling your pack behind you (at least 10’) also means that it won’t drag you down if you do go through the ice. Walking on your hands and knees or lying flat on a toboggan and pulling yourself along can also help spread the load.
  • Carry a long stick (8’-10’) with your arms crossed in front of your body and the stick held under your arms. That way if you do fall through the ice the stick should stop you from falling all of the way through. Carrying the stick in your hands generally won’t work, since you’ll most likely lose your grip if you fall through quickly.
  • Carry some ice picks so you can get a grip on the ice if you fall in and need to climb out. I like the retractable ones, but you can make a pair yourself with some nails sticking out of the ends of some short sections cut from a broom handle. [JWR Adds: The sharp ends should be kept capped with cork or drilled dowels, when not actually out on ice, for safety.] Some people like to attach them with a long string or line that runs up inside their jacket through their arms and across their back and leaves the picks hanging out of their ends of their sleeves for quick access. When I’m crossing ice I have them attached directly to my wrists with a lanyard.
  • Take short slow steps on the ice and roll your foot down from heel to toe for each step, and gradually transfer your weight after moving each foot. If you hear or feel cracking back off slowly and retrace your route back.

Ice cleats or crampons can help you maintain traction when walking on slippery ice. Falling on ice can cause a rapid impact, which can in turn cause the ice to shatter.

If someone does go through the ice you need to get them warmed up and dried out as quickly as possible. Have them strip out of their wet clothes and dry them off. You can actually dry someone off by brushing them with some light fluffy snow, but that doesn’t beat using that dry towel in the waterproof bag in your backpack. Wrap them in a blanket or sleeping bag and get them and their clothing in front of a fire as quickly as possible.

If you’re traveling in mountainous terrain one other hazard you need to watch out for are avalanches. Predicting and preparing for avalanches requires a lot more information than I can include in this article, but there are some good resources on the web that can get you started.

(To be concluded tomorrow, in Part 6.)


  1. Tunnel Rabbit – Thanks, but I’ve actually only scratched the surface. As I mentioned crossing frozen lakes scares me, so I’ve spent a lot of time talking to folks that have done things like ice fishing most of their life to learn as much as I can. Even if you’re confident that it’s safe to cross some ice, nature can still throw some surprises at you.

  2. JWR – good point on protecting yourself from the tips on the ice picks. One thing I’ve seen people do is dip the tips in a couple layers of Plastidip and let it dry. It protects them from the sharp points but the tips have no trouble punching through if you need to use them.

  3. This article is deeply informative and educational. Thanks to JM for writing it, and to JWR for posting it and providing such an important forum.

    I remember the loss of a young boy to a fall through the ice when I was also a child in the same neighborhood. Winters would freeze the surface of the water, and people would gather to skate across the ice. On this day, a couple of boys were out on what they thought would be a youthful winter adventure. Tragically, one fell through the ice, and succumbed to the cold. I have never forgotten. Ice does not always freeze uniformly. It can be extraordinarily dangerous.

    Be safe everyone!

  4. “Fresh snow on the surface should be safe to convert directly to drinking water, but you should look for discolorations or particles first to make sure it isn’t contaminated.”

    Any pure white snow I have melted has contained a surprising amount of dirt. I think any melted snow should be treated as dirty water as far as drinking it untreated is concerned.

    1. You are correct. In this regard, my chief concern would be metallic nano-particles. However, in most cases, we are not likely to get sick with parasites from snow water that has not been contaminated by terrestrial life forms. Snow contains traces of hydrogen peroxide that fizz out when it melts. This helps with killing pathogens, and it also helps seeds sprout quickly.

  5. Unless you are in complete “survival mode” a cup or two of tea a day is not a big deal as long you also drink water. I live close to 8,000 feet so I am careful to monitor my hydration. I have not observed any ill effects from a bit of tea now and again.

    1. Jake – you’re correct, and I was probably being overly general in my recommendations, but I figure it was easier to recommend avoiding it entirely than to try to provide a detailed explanation on how much is too much. It would also depend a lot on the person and conditions, and I just don’t have the depth of knowledge to provide that level of guidance. That’s why I emphasize that everyone should get some experience operating in winter conditions themselves so they can figure out what works best for them.

  6. If there’s ANY moving water under ice, DO NOT TRUST IT! On a lake, even a school of fish can erode the ice making it unsafe. Also, if the ice is clear, and you see lots of vegetation below, STAY OFF! The rotting vegetation will produce heat. Stay away from muskrat holes in ice, as they build up vegetation under the ice, and also on the ice to keep their hole open.

  7. Spot on with the cross country ski equipment. Most people in the states just go to a department store and buy the cheap cross country skis with the “fish scales ” and plastic poles.

    After just a few short hours of laboring with this cheap equipment they give up and declare cross country skiing useless. If you get a proper set of skis matched to your height and weight and use the right wax x/c skiing can be extremely enjoyable.

    Also more expensive but definitely much better carbon-fiber poles make all the difference with a proper set of skis. As mentioned skiing downhill with x/c skis definitely has its challenges and there’s no substitute for experience. Start small and work your way up to the bigger hills.

    Great article especially for those who like to play out in the snow 🙂

  8. Excellent article, water can also be easily melted with sunlight focused with a magnifying glass or fresnel lense(pocket magnifyer),artic canteens are available as surplus and allow greater volumes to be carried externally. Ice will stop travel more than anything else,a paper thin coat of ice can be too slippery to do anything but slip/fall. Slip on ice cleats for shoes/boots are available from most uniform/safety gear shops,snow/ice/mud chains for tires can make impossible travel easy(learn how to install/adjust before needing). If emergency ice crossing a ladder or a couple boards can get you across thin ice(if being chased sets up a trap for pursers)

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