Thursday, November 22, 2012

Into the cold


When spending days and nights outside at temperatures below -7 °C (20 °F) certain things become harder to manage.


* Your water will freeze...

- Empty and store your containers away before the temperature drops, otherwise they might become permanently damaged...
- Keep (and sleep with) only one container for your drinking water...  If the container is insulated it can help but only a little...
- Basic water filters are useless in these conditions... so if you need to filter your water either (1) boil it... or (2) use drops/tablets... or (3) use a UV method... like a "steripen" that can treat 1 liter at a time in less than a minute... also, use lithium batteries for your device as they have better resistance to the cold, and are much lighter...
- Your food will freeze... so better to store liquid food like cooking oil or sauces inside containers with a large opening instead of bottles with their narrow opening...
- If you do use a water bladder while hiking, make sure to always blow back in the hose once you are done drinking... this is to keep the hose empty at all time so water doesn't freeze inside...
- In a survival situation eating snow is not recommended... because the energy used by the body to heat it is not worth it... If you cannot make a fire, a small container in your hands can help melting a little bit at time...

* Fire will not be easy to start and maintain...

- Make sure you have a comfortable fire starting kit (a fire steel rod, a candle... not just a lighter because gas does not work well below 0 °C)
- Always carry good tinder material with you and if you do not have enough pick some on your way (birch bark, vaseline + cotton, dry grass, shredded wood or ideally cedar bark...)
- If you want to start a serious fire, do not do it on frozen ground or snow, always put a layer of thick wood first...
- If everything is frozen or wet, you might have to split thick logs to expose the dry parts... also the cold can make wood harder... so make sure you have the right tools and know how to use them... (1) a good backpacking saw is light weight and very easy to use... as well as (2) an axe is a must... but it heavy, and there is a learning curve, accident can happen... (3) if weight is an issue or you cannot carry a an axe for any reason, a thick survivor knife for splitting is considered a minimum... the thicker and the longer the blade the better... a very big camp knife on which you can hammer with a piece of log is an easy and safe way to split wood...

* You might get cold...

- If your hands get too cold, do not blow on them... your breath is humid and it will make it worst... put them against your body under your arms or between your thighs instead...
- Your sleeping bag is better if it is not too big for your size... you will get more heat... unless you want to use the bottom to store your water...
- It is a good idea to heat water and put it in a bottle and put that bottle in your sleeping bag when you go to sleep... You can also wrap it in a shirt so you do not burn yourself... You can use more than one bottle...
- When it is very cold, it really matter if you have a sleeping bag that is rated close to the lowest temperature your are expecting...
- The ground takes away most of your heat, so a good sleeping pad is very important... otherwise you can always make a bed of leaves... the best way to make an insulated bed in the snow is to use branches of trees with needles like pine, fir or cedar... this sort of bed has to be renewed ever 3 days as the needles fall...
- Use your layers smartly... Always adjust... Do not overdress, sweat and get wet!... Forget cotton, always use wool even for your first layer... It will keep you warm even if you get wet... Wool also prevent moisture and bad smell... Wool is always the best choice... Animal skin is excellent but very heavy to carry around in comparison...
- Hand-warmers can help for a night or a day, but do not rely on them. They are extra weight and they do not last forever...
- While moving around, protect your hands and feet... specially when using water... avoid early morning... wait for the hottest hours of the day to brush your teeth or wash parts of your body...
- If your sleeping bag and your clothes are not enough, you will need to use a fire to keep you warm. There are ways to set up your shelter and your fire in ways that will optimise the heat. You could hang a tarp behind you in an angle, to reflect the heat of the fire. A wall opposite you - a big rock a cliff or a few logs on top of each other - will reflect even more heat. (Checkout bushcraft manuals to learn about how to build winter shelters.)

* Over time, condensation will gather in your sleeping system and make it wet...

- This is because of the big temperature difference between you (and your system) and the outside world... On long trips this can be a serious issue... Even synthetic sleeping bags will loose most of their properties at some point... When temperatures are very low this can be a serious issue... Even if your shelter/layers are "breathable" like Gortex or Event, if they are waterproof, you will for sure get some condensation...  The solution is not simple because you do need a waterproof layer for the rain/snow/wind... In general, if you are close to 0 °C you need to protect from the rain but if you are way below that, in arctic conditions, then you do not need to protect from rain, only from the wind. This is why arctic cloths are different - sometimes a bit like thick canevas - to make them breathable.
- To prevent your sleeping bag from getting wet from the inside, do not breath into your sleeping bag during the night... to avoid condensation, you must always allow good ventilation... so if you want to protect your face use a wool scarf or balaclava... If you are in a tent, it is the same problem, to prevent the inside of the tent (and therefore the outside of the bag) of getting wet, make sure the tent has enough openings to allow air flow and control the condensation...
- If a down sleeping bag gets wet it will become useless... On long trips, day after day, your bag gathers the moisture from your body... with time, it becomes less and less efficient... unless you manage to dry it during the day, which is not very easy.... If you insist on using a down sleeping bag (more compact and lighter than synthetic) try to pick a bag that is water repellent... and make sure it can be fully opened to dry it easily if it gets wet...
- Be ware of waterproof bivy sacks... If it is very cold and the only thing you have is a waterproof bivy sack, the dew point will always be inside the sack, and you will get fast condensation inside... Most advanced hikers prefer a non-water proof bivy sack or cover for their sleeping bag... and a ventilated tent or light tarp for protection from the rain/snow/wind...

* If you are traveling on thick snow... you might need a few special tools... 

- skis or snowshoes (raquettes) to stay on on top of the snow...
- walking sticks...
- sunscreen and sunglasses to protect your face from the reverberation on the snow... if you have no glasses you can build some with tree bark or cardboard...
- a wide snow shovel is very practical around camp... there are some compact backpacking models that weight only 550 g to 700 g... 
- you can also use snow to make (or improve) your shelter...
- to cut blocks and build an igloo you will be happy to have a long "snow knife" or snow saw...

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