If you’re not careful, it’s very easy to become dehydrated in the winter particularly if you’re engaged in sports like snowshoeing, backcountry skiing or mountaineering. Under these conditions, it’s not enough to be on the lookout for yellow pee; you need to hydrate before exertion and regularly during all outdoor activities.
Dehydration is accelerated in cold weather or at higher altitudes because the air we breath is drier. Normally, people lose between one to two quarts of water a day via evaporation from the lungs. When we breathe, our bodies humidify dry air and heat it up to our body’s temperature, which is why your exhalations look like fog in cold weather.
In cold weather, your body has to work harder to humidify the air you breathe and to warm it up, meaning that you need to drink more water and eat more if you are outdoors. A good rule of thumb is to drink at least 4 quarts a day, but many people will drink twice that under high exertion levels or over 10,000 feet of altitude.
Psychologically, it’s easy to skip hydration breaks during winter activities because you are less likely to feel thirsty. But the consequences are much higher, as dehydration can accelerate hypothermia, frostbite or fatigue.Therefore, you need to pace yourself accordingly and drink and eat at frequent intervals to keep up with the demands of your body. I always carry a watch with me outdoors, and make a habit to drink and eat at regular intervals.