As exposure to a cold environment over time itself will affect combat readiness, making sure that your people get a good rest is important. A key factor here is setting up your bivouac in a way that facilitates this. The cold does present some challenges that we do not see in the warmer seasons, and as such a tent or other type of shelter that provides good protection from the elements is preferred. For survival situations, there are also forms of improvised shelters that can be used. An emergency shelter should be readily available in case of sudden weather changes.
There are several different tents available in the market today, everything from cotton canvas tents to dome and tunnel tents made from modern lightweight fabrics. Regardless of types being used, there are certain features that are desirable, such as light weight, low height, and small volume so it heats up faster, a degree of water repellency, breathability to avoid condensation, windproof and wind-stable, lightproof and with good ventilation.
The first thing to consider is where to establish your bivouac. You want to avoid placing it near a body of water or in a depression in the terrain, as those spots are usually colder. You preferably want to find a place that will give you shelter from the prominent wind direction, a piece of flat or lightly sloping terrain and a location that provides some camouflage. You can use skis or snowshoes to flatten out an area and pack the snow. Avoid windy summits.
If there is enough snow, the ideal solution is to dig down and place the tent there. This will also provide some protection against weapons effects – shooting through snow does funny stuff to bullets, although you need quite a bit of snow to call it cover. If you cannot dig out a hole for the tent, you can build a protective mound around the tent or use the terrain for protection. Note that if you bury the tent or build a mound around it, snow carried by wind can land on the walls and roof of the tent and should be removed regularly.
If you do not bury the tent or build a mound around it for protection, you should build a windbreak around the tent. The purpose of this is to prevent the wind from grabbing hold of the tent or to prevent snow from building up on the tent. The construction of a wind break requires a bit of work and time and needs to be assessed in relation to the tactical setting. The windbreak should be constructed on the side of the tent that faces the wind and should be half the heigh of the tent. If time allows, build the windbreak all the way around, as the wind direction can shift as time goes by.
The sides of the tent that are on the ground should be packed with snow, to increase insulation and negate any wind effects. If the tent has storm flaps, these must be folded out and covered with snow for the same reason.
Now to cover the inside of the tent. If you are setting your tent up on top of snow, it is very helpful to build a work pit. A work pit is a pit that is 60-80cm deep, dug out in the entrance of the tent. It allows you to place the heat source correctly to reduce noise and to reduce the risk of fire, as well as reduce the thermal signature of the bivouac. It also gives you more space to work when carrying out stove watch duties, such as melting snow and preparing food and it provides space to organize the equipment inside the tent.
Regarding this organization, one side of the tent is considered “clean” and the other is considered “dirty”. This is to ensure proper field hygiene. “Dirty” equipment is things such as the stove, fuel for the stove and garbage. The “clean” side holds food, your “snow bag”, pots and pans etc. This is important as we do not want to contaminate our food or water – we use kerosene as our main fuel, and it is not very good if digested, as it causes diarrhea. A “snow-bag” is a clean bag that you put snow into for melting. It needs to be collected from a place with untouched snow, and you should use the snow closer to the ground as it has higher water content.
We want to bring as little stuff inside the tent as possible. If you can, build equipment pits outside where you store your rucks, skis, snowshoes etc. Build your weapon rack and store weapons outside to prevent temperature fluctuations which can cause freezing issues and cover them to protect them from snow fall or wind blowing snow on them. All depending on the tactical situation, of course. A good tip here is to organize things in your pack in compression bags, and to have one of these designated as your “tent-bag”. This minimizes crowding.
Heat sources come in a variety of models, and they all have the same function – to melt snow for water and to warm up the shelter. That is one of the main advantages during winter – water is everywhere, so no need to carry extra. A liquid fuel model is preferred, as gas can have issues in extreme cold. If possible, snow melting should be done during daylight, as this will help reduce the thermal signature during night.
For some units, depending on the tactical situation, what we call “hard routine” is required and this means that they are only setting aside a short time slot every day to melt snow to eat food or fill up canteens or thermoses. The rest of the day/night the shelter is cold – this is to reduce the thermal signature of the tent. This is very demanding, but the mission requires it as the risk of detection is high.
Insulating yourself from the frozen ground is important. Snow does this very well so, if possible, make sure there is snow between you and the ground. A sleeping mat is also very important, and it should be sufficiently thick to provide good insulation from the ground or snow. Placing twigs or spruce twigs on the ground before placing your sleeping mats is ideal. Also make sure that the sleeping mats overlap inside the tent, to avoid cold spots.
If you are using a stove, you need to always have someone on stove watch. While they can do tasks like melt snow, prepare food, perform maintenance on their equipment, dry clothes etc, their main function is safety. This relates to two things; fire and carbon monoxide poisoning. As such, they must always stay awake, and always have a water canteen and a knife at hand in order to cut an opening if the tent catches on fire. If a stove goes out for some reason, it can leak CO fumes into the tent, and exposure can be lethal to the occupants – it is odorless, so it cannot be detected.
Establish a common “piss pit” and latrine for the entire unit, to ensure that “personal business” is done at the same place. Facilitates proper field hygiene.
Make sure that you have a “track plan”, meaning that you establish a track throughout the bivouac area where people can walk, in order to reduce the visible signature. This also extends to where you collect snow, twigs etc – maintain tactical awareness so that you don’t reveal your position.
One of the most important field routines regardless of climate, but especially important during winter, is to maintain control of your personal equipment. Never just put anything down on the ground, keep everything on your body. If the weather is bad, putting your headgear or handwear on the ground can result in you losing them in the blink of an eye – covered in snow or taken by the wind. Without this vital equipment, you will begin to struggle. This applies everywhere – once you are done using an item you put it back in your pack or your 2nd line gear.
Establish a buddy check system, where each buddy pair is responsible to help each other out with various things, such as checking for frost injuries during short or long halts, one keeps security while the other gets dressed or removes clothes during a halt and so forth.
Before going out on an operation, you need to perform proper Pre-Combat Checks (PCC) and Pre-Combat Inspections (PCI)– it is too late to discover that your snow shovels do not work, or that your tent is leaking or that your stove is defective when you are out in the field. This is a leadership responsibility and must be followed up.
In the military we use a term called “priority of work” – this defines which tasks should be completed in which order, and sometimes with a time consideration. You should establish a priority of work list for establishing a bivouac area. The first priority is always security. After that you have establishing the tent and bivouac area, conducting maintenance on personal and squad equipment/vehicles, establishing watch lists for both the guard post and stove watch, personnel inspection for overall health but with a focus on cold/frost injuries, reporting in needs for resupply of all classes and so forth. These are all parallel processes, and leaders need to assign tasks directly to personnel. After that, people need to eat and to start going to rest. That is the main reason why you took the time to establish a bivouac, so this needs to be the focus.
Hydration and nutrition are two very important aspects in the cold. You should strive to have one hot meal per day. You should also drink small amounts throughout the day, and refill your canteen using snow. No need to gulp down a whole canteen, as you will only piss out what your body can’t take up. People always say drink “tons” of water, but electrolyte balance is the important thing. Avoid diuretics in the field and avoid sugary drinks as they have a negative impact on water uptake. You are more likely to be dehydrated in the cold, as you do not have the same thirst sensation as you do in warmer weather, and you will also experience cold diuresis. Water will eventually freeze regardless of the container – the best tip I have is to use a bottle with a wide opening and to store it in a pouch upside down. You can also carry under your clothing, on a string around your neck. Not very comfortable but keeps the water from freezing.
Some people will claim that a warm meal and a warm drink will “heat you up”, but that is actually not true. The correct way to explain it is that your body does not have to expend energy in order to heat up the food once it gets into your digestive system. The consequences of insufficient food and water is much more serious in a cold weather environment than during the warmer seasons, as it directly affects your ability to prevent cold injuries, maintain combat readiness and maintain physical and mental capacity.
Weapons maintenance in the field during cold weather is a highly debated topic, and I see a lot of “strange” recommendations. It really isn’t that difficult – they key is to make sure that you have a good coating of oil on the reciprocating parts and glide surfaces inside the weapon, and also make sure that external controls have sufficient lube. I am not too concerned with the type of lube used – in my time in the military we used BreakFree CLP, and it works fine. Don’t cut your lube with anything – the lube displaces water and snow and prevents freezing. Remember, during extended operations the environment is more likely to cause issues with weapons than excessive build up from shooting. We used to carry what we called a “Texas-rag”, a piece of cotton strings soaked in lube carried in a zip lock bag. We would use this to wipe down our weapons. Try to always keep them in the same working temp, to prevent melting and freezing issues. This is harder for vehicle-based units, such as mechanized infantry. If you store weapons outside when you bivouac, cover them up so that they are protected from wind and snow.
A good piece of kit to remove snow from your equipment and weapons is a small nylon brush, kept in your 2nd line.
Don’t shave in the cold – your skin is covered by a protective layer of fat, and shaving removes this and increases the risk of cold injury.
As stated in the Cold Weather primer, the devil is in the details and you will need strict adherence to your SOP’s to be successful.