How the winter cold affects you

A normal, naked human body functions best when the air temperature is 27°C. One way of defining the word “cold”, then, is any temperature below 27°C. Below this temperature we need to be proactive, whether by adding clothes for protection, going inside or moving around to raise our blood circulation. Wind and rain dilute our perception of the cold.

There is a saying in Greenland that “if you sweat, you die”. This might be a little drastic, but it illustrates a point - when moisture enters the picture, frostbite often becomes an issue, even at temperatures above 0°C. Water conducts heat 25-30 times better than air and rapidly transports energy away from the body. (Air, on the other hand, is a poor heat conductor and provides insulation – a characteristic that sweaters, down jackets, sleeping bags, etc., make the most of.) This is why sweat, snow and water are actually a threat to your well-being, particularly if you are on a long trek and are unable to dry your clothes and equipment at the end of the day.

Wind and wind chill

When the wind is not blowing and you are standing relatively still, the air around your body warms up and acts as a layer of insulation. If the wind starts to blow, this warm air is pushed away by new, cold air. Your body reacts by once again warming up the air around you. If this continues for a long period of time, your body temperature will drop.

The more the wind blows, the cooler you become. At a temperature of –15°C and winds of 8 metres/second, the wind chill factor on your bare skin is the same as wind-still conditions at –34°C. This relationship between the wind, temperature and effective temperature on your bare skin is illustrated by the wind chill index below.

 

Wind m/sec	Air temperature °C
0	0	–5	–10	–15	–20	–25	–30	–35	–40
2	–1	–6	–11	–16	–21	–27	–32	–37	–42
5	–9	–15	–21	–28	–34	–40	–47	–53	–59
8	–13	–20	–27	–34	–41	–48	–55	–62	–69
16	–18	–26	–34	–42	–49	–57	–65	–73	–80
25	–20	–28	–36	–44	–52	–60	–69	–77	–85

The wind chill index shows the effective temperature on bare skin at different wind speeds

Winter conditions

From a pure meteorological perspective, the definition of winter is when the average temperature over a 24-hour period is below 0°C. Cold, winter-like conditions can occur at any time during the year, particular at high altitudes. However, if we ignore this theoretical definition of winter, a common, but more relaxed, definition of winter is the arrival of both snow – as well as the advantages and disadvantages snow brings – and cold temperatures. But winter does not necessarily mean temperatures in the extreme minus; rapidly changing weather often causes problems when temperatures fall and wet conditions freeze. This type of variation at relatively mild temperatures can actually be more difficult to handle than persistent, extremely low temperatures.

Snow - both friend and foe

Snow often makes it easier to move through nature since you can glide on skis or pull equipment on a sledge. You can melt snow for drinking or dig a bivouac or hole to wait out bad weather. But snow can also test your ability to navigate since snow-covered contours and landmarks take on a different appearance than when they are bare. Heavy snow can quickly eliminate all visibility, and snow that drifts up the sides of mountains can, if the wind is strong enough, quickly turn into a potential avalanche.

In order to enjoy your experience, you need to know some basics about how to adapt to the snow. The follow-up question, naturally, is then “So, what do I do?”. One of the primary things you need to do is let go of some of the mental blocks and preconceptions that you may have and focus directly on the uncertainty that affects how you react to the cold. This means you should spend a lot of time outdoors in order to gradually discover what winter is like and how beautiful it can be. When Mother Nature then unleashes one of her disagreeable outbursts, you will be better prepared mentally and will be able to make smarter decisions. You will also be able to tackle the challenges winter throws at you, and you will find it easier to “dig deep” in more difficult moments.

In short, there is a long list of reasons why you should prepare for a winter trek differently than you would for a summer trek. But with the right preparations and equipment, almost anyone can learn to handle the cold – and therefore also safely appreciate its beauty.

Prepare yourself physically

A long mountain trek requires that you prepare yourself both physically and mentally. Regardless of how many days you have planned to hike, you will expose yourself to stresses that you rarely experience during your normal daily schedule. You leg muscles, feet and willpower will be tested and the more prepared you are the more you will enjoy the gurgling brooks and dramatic mountain tops.

1) Start early

Your general fitness level is important for long hikes where you are carrying your lodging. Your heart and lungs are going to have to work hard, which means that you need to be in relatively good shape to be able to enjoy the nature. If you are not physically active year-round, you should start training no later than six months before you go on a long trek. Hiking, biking, running and swimming are all good activities to build up your fitness level.

 

2) Trekking in mountainous terrain

Your leg muscles, knees, feet and joints will be exposed to extreme stress. In order to help your body become accustomed to these stresses, you should try to create the same conditions as your adventure. Hike in stony terrain and up and down hills or mountains. Try to take a long walk at least once a week.

 

3) Get used to a backpack

Carrying a heavy backpack can feel uncomfortable at first. It weighs down on your shoulders and hips and your steps become heavier. But if you start with a lighter pack and slowly increase the weight, your body will get used to the load. Slowly add to the pack until you reach the weight you will carry during your trek. You do not want to shock your body - this can lead to serious injury.

 

4) Break in your hiking boots

Make sure you have broken in your hiking boots before you go on your trek. There is nothing worse than having to cut a trip short due to blisters. To be really sure that your boots fit well, we recommend that you walk at least 200 kilometres in them before going on a long trek.

 

5) Don't overtrain

Hiking in the Swedish mountains is difficult but it is not like climbing Mount Everest - it is important that you do not overtrain. Before the trek, you should eat healthily, get plenty of sleep and not train so hard that your muscles and joints become sore. The objective should be to start your trip with a rested, strong body.