I went out in January as well, when it was -5C, and in the past I have slept out as far as about -15C overnight and -8C during the day. My personal limit would be anything past -20C, not because I don't think it would be fun and/or safe, but because I don't have the funds to buy more extreme-cold weather gear. Nor do I plan on buying extreme-cold weather gear, as this is an expensive investment for only a very small part of the year--and where I live, it is very rare that it drops below -20C even in the coldest part of winter.
So up to my personal limit of -20C, what I'll do is answer some frequently asked questions people have posed to me about the season that is often neglected, even by those that enjoy backpacking in the other 3 seasons. I seem to have been asked more questions the past few months due to going out more this winter, and with more members joining my camping club at school.
If you plan on backpacking in temperatures lower than -20C, I suggest you make sure to do your homework and research, prepare, and plan as much as possible. You might want to read a few books covering more advanced winter camping, or go to camping forums and ask around for more advanced tips. The colder it is out, the more consideration you must take on your trips outside, especially if you are going to be sleeping out there!
Here we go, and if there are any other questions you'd like answered, just email me and I would be happy to add it to this post. There are lots of great articles out there that I will link in my answers for more details and information.
Q: You're going out into the woods and sleeping in the middle of winter?! Are you crazy!?
A: Yes. No.
Q: You're going to freeze to death!
A: No I'm not. Shut up. That's not even a question.
Q: What kind of clothing should I wear to go winter hiking/backpacking/camping?
A: Avoid cotton, first of all. Synthetic fibers like polyester work well, as does wool. Down feather clothing is ideal, but expensive.
Q: How do I layer clothing?
A: First a disclaimer: Everyone has different reactions to the cold. Some people have high metabolisms or tolerance or for whatever reason can deal with the cold easier than others. I will explain what works for me (and I tend to deal with the cold better than some).
Depends how cold it is, and how much you are moving. Your upper body/torso is more important to keep insulated, because that is where your vital organs are. I have found that I am comfortable around 0C with three (upper or torso) layers, down to -5C with four layers, and down to -10C with five layers. Past -10C I will substitute certain thin layers with thicker, warmer ones to get down further. If I am hiking or doing something active, I will simply remove a layer or two.
An example of what I use for when I have five torso layers are: polyester long sleeve shirt, wool sweater, polyester fleece jacket, synthetic vest, water resistant jacket. I will switch the jacket for a thicker winter overcoat if it dips below -10C.
For my lower body: polyester long tights, nylon hiking pants, and wool socks are usually all I need. If it gets below -10C, I will also wear snow pants over my hiking pants.
First layer you wear is called a base layer. These are often polyester or wool tights, wool (especially merino wool) being warmer but much more expensive. Next you have your mid-layers, or insulating layers, such as a sweater, vest, or jacket. There are lots of different kinds of combinations and types of insulating layers, and the price can range quite a bit. A synthetic vest can be quite cheap, versus a high-end down-feather vest which can cost more than some people's entire backpack full of gear.
The last layer is called the shell layer or outer layer. This ought to be at least water resistant, if not water-proof. High-end shell jackets that are water-proof and breathable can cost quite a bit, but there are lots of affordable water resistant jackets and coats. You can also buy water-proofing sprays and waxes for your outer layer. It should go without saying to have gloves (maybe even two pair), hat, and scarf.
Here is a good video on how to layer from an ultra-light perspective, though this system is not intended to be used too much further past freezing, as stated in the video, without some adjustments.
There are people that also use vapor barrier clothing to keep warm, but after a few experiments with it, I found it generally too uncomfortable for me, but here is a good (and long and very detailed) article about it. It should be noted that some people, like the author (a professional who has backpacked around Alaska in VERY cold weather for months), swear by VB for being effective and good for saving weight on clothing.
Q: Holy crap, good winter sleeping bags can cost a lot of money! Any alternatives?
A: Yup. Many backpackers have a summertime sleeping bag and a 3-season bag, or a few different kinds of sleeping bags, or maybe your boyfriend/girlfriend/mom/dad/etc. has an extra sleeping bag laying around. Simply use two sleeping bags. I have found that using my down feather 3-season bag inside of my wife's 3-season synthetic bag works great. Just make sure to test out using both bags at home to see if they will work together, and it's also a good idea to take them outside (or maybe on your balcony if you live in an apartment) and see now they handle the cold.
Q: Good ground insulation (i.e. sleeping mats) can also cost a lot of money! How about an easy fix for that?
A: No problem. Again, most backpackers have a summertime mat and 3-season sleep mat, especially because of the low cost of foam mats. Like the sleeping bags, you can use them both. R value (a number given to how well something like sleeping mats insulates you from the ground and keeps you warm) stacks--for example, a summer mat has an R value of about 1 usually, and a 3-season mat has an R value of 2-3, so used together you have an R value of 3-4.
Only have one sleeping mat? Well, this ought to be a 3 season mat, so just buy a cheap foam mat to go with it, and now you have a mat for the summer too. Also remember that you can use other gear to put under you for insulation too, like your backpack, sit pads, etc. And you can also use natural material like dead grass/reeds and/or pine branches too, but please respect nature!
Q: I get cold so easy when I sleep! Any other tips on how to keep warm?
A: Sure. Sleep with all your layers on at night, and use everything you can put under you for insulation (see above).
Take a space blanket with you (here in Sweden they only cost 30 SEK at Jula or Clas Ohlson) to use as either a vapor barrier inside of your sleeping bag, or a heat reflector on top of your sleeping bag. If you use it on top of your sleeping bag, make sure to place it lightly on top of you, or hang it next to you (say on the wall of the shelter you are sleeping in, e.g. the side of your tent) so condensation does not gather on it and get you wet.
Wear a different pair of sleeping socks to bed (or two pair of socks), along with gloves and a scarf.
Another good trick is to eat a rich late-night snack to make sure your body has enough energy to keep itself warm that is readily available, like a bar of chocolate or some salami and cheese.
You might want to consider buying a higher quality sleeping mat with a R value of 4-6 if you are a cold sleeper for winter camping. There are even mats with down feathers in them that go up to as high as R value 9-10, but they ain't cheap or lightweight.
Q: How do I keep my water from freezing, and how do I gather more water?
A: Put your water bottle in your pocket or inside your jacket while you are walking, and/or inside your sleeping bag at night.
To gather more water, find clean, untouched snow and fill your bottle, then put it in your pocket/jacket to melt. Or you can melt the snow over a fire or stove. While it might be hard to gather water from a lake that is frozen solid, you can break pieces of ice to melt with a rock or strong stick. Or find moving water, like a stream--and many lakes have streams that feed them, just check your map.
Q: When is it safe to walk across a lake?
A: There is no easy answer for this to cover all situations, but if it has been below zero and stayed below zero for several weeks, the entire lake looks frozen, and the ice does not break after carefully testing it, it's usually safe. Note: usually.
There are many factors in how safe ice is to walk on, and as a general rule, there is no such thing as 100% safe ice to walk on because of this. So use common sense, make as many observations of the environment as possible, talk to locals if possible, and test the ice first with some rocks or logs.
Always carry your knife or keys where you can get to them quickly in case the ice breaks, so that you can use these as tools to pull yourself out of the ice.
Here is more information on the subject that is worth looking into if you want to hike or camp in the winter, especially if there are a lot of lakes in your area, like there are here in Sweden.
Those are all of the questions I got recently off the top of my head. I hope this helps some one to go out and enjoy the many wonderful aspects of winter camping. No bugs, less people out, the beauty of snow and ice, and not to mention how fun snow and ice can be. On our trip we cleared a spot of solid lake ice and had lots of fun and laughs running and sliding to see how far we could slide, not just on our feet, but on our bellies and backs and butts too. Our club's next trip we will go sledding, if possible.
Don't let the cold intimidate you! With a little extra planning a whole new and exciting kind of backpacking awaits.