It is possible, and even desirable, to hike all year round to maintain a good physical condition, and not to lose what we have gained in endurance through the summer season.
We will deal here with trail or off-trail hiking in the countryside by voluntarily excluding high mountain hiking during the winter.
When I say high mountain hiking, I refer to mountaineering which is supposed to take place at higher altitudes and involves climbing and mountaineering experience.
From 10,000 ft (3000 m) above sea level, you can be considered to be involved in mountaineering.
But the altitude criterion is not enough: mountaineering is an exposed practice, i.e., it poses a potentially fatal risk in the event of a fall.
It requires a clean technique, to be able to walk on snowy slopes, on edges, or to climb a wall. As they progress, climbers secure themselves with a rope, balance and hold themselves with an ice ax and crampons.
All these characteristics distinguish mountaineering from mountain hiking or just hiking in a forest or in a valley, which requires only a few places where hands will be used or use a fixed rope to climb.
Needless to say that high mountain hiking during winter involves even harsher conditions due to very low temperatures and very deep snow.
A brief physiological reminder
Regardless of the ambient temperature, the body will always try to maintain its core temperature at around 98.6° F (37° C); when it drops, we will say that there are regulatory failure and hypothermia.
To fight against the cold:
– we will try to reduce body’s heat loss with good clothing protection; the body, as a reaction against the cold, will reduce the size of the vessels that carry warm blood to the extremities such as hands and feet to further limit this heat loss.
– It will also try to increase the amount of heat produced. Shivering is one way, but it is not sufficient enough, motion and effort, on the other hand, will create a significant amount of heat since 75% of the energy generated to provide the effort are transformed into heat.
What are the specific characteristics of winter hiking?
- The days are significantly shorter: they force us to reduce our itineraries, in order to avoid returning at nightfall; it then becomes more difficult to find our way around, and the outside temperature will decrease more quickly at the same time when your organism that has made an effort during all day, becomes tired and less resistant.
- It is colder: the outside temperature is lower, it is not uncommon to observe freezing temperatures at least in the morning and evening.
There is also an essential notion to consider right away, the temperature is not the only indicator of cold: the movements of the air, the wind in particular considerably increases the sensation of cold.
A sheltered thermometer will always indicate a higher temperature than the same instrument exposed to the wind.
To quantify this effect, meteorologists calculate the perceived temperature or wind chill index using an empirical mathematical relationship, which takes into account air temperature and wind speed.
This information is particularly useful in regions with harsh climates (Canada, Northern United States, etc.). It allows us to take preventive measures against damages caused by cold (frostbite, hypothermia, etc.).
A wind chill index is a number without units. At an air temperature of 46° F (8°C) and a wind speed of 18 MPH (30 km/h), for example, it will feel like 39° F (4° C).
It means that the sensation on the skin will be similar to that experienced under a temperature of 39° F (4°C) on a windless day.
We don’t even dare to consider freezing temperatures…
- It is humid, and it can rain or snow: the ambient humidity is not a factor of aggravation of the cold.
On the other hand, the humidity of the clothes, whether due to sweat or precipitation, will lead to a very high loss of heat by convection. Moisture escapes from the skin, saturates the air around the body and condenses on the surface of the skin, so if the underwear (1st layer) is effective, condensation will occur especially in the insulation layer rather than near the skin.
What are the risks involved in winter hiking?
- To get lost if it is dark and you don’t know your itinerary well.
- Be the object of complications due to cold: hypothermia or lowering of the core temperature, disorders of the extremities with numb fingers, chilblain, exceptionally frostbite, since, as we have seen, due to the vasoconstriction of the vessels of the extremities, they receive less heat and are also less well supplied with oxygen and nutrients.
How can I avoid these troubles?
1- Prepare your hike well:
- The route must end before nightfall,
- It must avoid passages through places exposed to the wind.
- Finally, you should not hesitate to give up in the case of really terrible weather
2- Proper winter hiking clothing:
Dress appropriately: warmly at the start of the hike; you should not hesitate to take off some layers of clothes as soon as the heat produced by the body becomes significant and causes discomfort; on the contrary, you should immediately cover yourself during breaks or stops.
The ideal regarding clothing protection: the 3-layer system:
- The first layer – Its function is to prevent body moisture from remaining on the skin by dissipating evaporation over a larger area and into the outer layers. It must be skin-tight, comfortable, non-allergenic, dry very quickly and resist frictions.
- Avoid cotton (especially 100%) as it absorbs moisture rather than disperses it and is ineffective when wet. Wet cotton also feels cold.
- Wool absorbs moisture but remains relatively effective. It sometimes irritates, especially if it is wet.
- Polypropylene (and other synthetic materials designed for this purpose) does not absorb moisture and repels it. It is resistant to friction, easy to wash, dries very quickly and is anti-allergic.
- Silk is warm and comfortable to wear. It does not absorb moisture, but it is not very resistant to friction.
- The second layer is the one that insulates from outside air and retains heat. Its function is to maintain a thick layer of air around the body and to release moisture to the outside. It must dry quickly, not hinder movement and blood circulation.
- Synthetic materials can retain up to 80% of their effectiveness when wet (such as Thinsulate and Quallofil which replaces down).
- Natural fibers (except wool) vary between 0 and 20% efficiency when wet.
- Polar insulation (polyamide) is lightweight and does not retain moisture. For the same weight, synthetic fur is twice as warm as wool.
- Wool is a good insulator that keeps warm even when wet.
- Down is an excellent insulator when dry but loses up to 80% of its insulating capacity when wet.
- Finally, the third layer is the one that will directly face the outside conditions. Its function is to cut off the wind and prevent water or snow from entering. It must also allow moisture from the body to escape through the fabric. This layer of clothing should be chosen according to the outdoor conditions and should fit around the neck, wrist and waist and not be too tight, have a hood, not trap snow and ideally have a zipper with flap.
- A very tightly woven fabric breathes well (allows moisture to escape) and provides moderate protection against air penetration. It has low impermeability.
- A laminated fabric (GoreTex, H2n0, etc.) breathes moderately, is wind and snow resistant. It has an acceptable waterproofness. It’s a pretty good compromise.
- Waterproof fabric is wind and rainproof. It does not breathe (does not allow moisture to escape) and causes interior moisture accumulation. Ideal for heavy rain or marine conditions.
3- Take special care of exposed extremities and parts:
- A beanie or a cap should protect the head from the high vascularity of the skin that can let a large amount of heat out.
- The gloves should be insulated and covered with a waterproofed fabric in the event of precipitation; silk or insulating undergloves for more sensitive people; the latter will have better protection if they use mittens.
When gloves are wet, they lose their insulation and also increase conduction cooling. Ideally, you will have an extra pair; if not remove them and protect your hands as best as possible (pockets, underarms).
- The socks, woolen or made out of modern material with high insulating ability, should be kept as dry as possible by using breathable but waterproof hiking boots.
After use, these boots should be carefully stored after cleaning and after receiving any specific treatment from the manufacturer.
- Carry a warm and mainly dry change of clothes in your backpack, stored in a waterproof bag (garbage bag) as backpacks are rarely waterproof.
4- More tips!
- Survival blanket: very useful in the event of an accident, it can allow us to build a shelter in the event of nasty weather or offer the victim better isolation.
- Food: rich in slow sugars the day before, don’t hesitate to snack more often, because you eat more in winter when hiking as you tend to lose energy faster.
- A thermos with a hot drink (soup or tea) will warm the body…and the heart on your brakes!
How is hypothermia recognized and what to do?
When winter hiking, hypothermia rarely shows the possible severe character that we could find in high mountain hiking, but it is important to know how to recognize it.
The individual is most often pale, tired, he walks with difficulty, sometimes drowsy, often disinterested in his environment.
His body temperature regulation is failing. It is then necessary to help that person to reach as quickly as possible a place where the temperature is more pleasant or even comfortable, to put him at rest and make him drink hot drinks (tea, soups…) until his body can produce the necessary heat again.
The extremities, the hands, and feet?
As soon as your hands or feet are cold, check that your gloves or socks are dry and that your fingers and toes are not too tight.
If your hands are too cold, circular movements of your arms will allow better circulation and if needed stick them under your armpits for a few minutes (without your gloves, of course!).
Here again, we will not talk about severe frostbites. However, exposure to cold and humidity can cause “chilblains,” frostnips and superficial frostbites on the fingers and toes.
The fingers are cold, pale, numb, their sensitivity reduced.
The heating should be done gradually, avoiding putting them on a radiator or immersing them in hot water.
Circulation recovers, fingers turn pink if not red; this phase of even gradual warming is often transiently painful.