When it comes to experiencing real THIRST, most people think of a hot, hot desert trek across the frying sand dunes...but actually a trek behind a dog team across the frigid tundra gets our team right in there with the people who need to be careful of drinking plenty of fluid. "We drink like camels" says Paul.
For one thing, the Arctic is a dry desert with very little humidity (moisture in the air). In a hot desert we lose liquid as we sweat to lose heat; in the cold we lose water to moisten the cold dry air we breathe.
And our team is not exactly sitting around. As hard as they work they lose plenty of water through exercise.
Did you know your body loses more water than it gains from eating snow? - And that your body is 70% water.
Enjoying lunch with an all important cup of Lipton tea out on Hudson Bay at -30° below zero.
An adult normally loses about one liter of water a day through evaporation from the skin and lungs. During a day of strenuous activity, a person can lose 10 liter (2-3 gallons) of water. (Try the experiment below once to really get the hang of this).
The tricky part for our team members is that you don’t notice sweat so much in the cold because it evaporates more quickly in the dry winter air. Also the high-tech clothing wicks sweat away making you feel like you are sweating less than you really are!
Also, in the cold you tend to think less about drinking, and if you wait until you feel thirsty you are actually behind since "thirst" indicates that you are already dehydrated!!
If you ask Mille, she will tell you she finds it quite difficult to drink that much. But if she doesn’t drink it she will get sick from dehydration. Dehydration worsens fatigue, decreases our ability to exercise efficiently and reduces our mental alertness. You can even go into shock. In short, dehydration is very dangerous and in worst case may lead to hypothermia – a deadly condition.
Staying hydrated is simply a cornerstone in arctic traveling.
So how does the team get water then? They spend a big part of the day watching over a teapot filled with ice and snow (and a little bit of water or you will burn the pot) on the two burner camping stove. To be exact, 3-4 hours a day are spent melting ice and snow into water used for tea, soups, powdered milk, hot chocolate, sports drink and whatever needed for cooking. Each team member tries to drink at least a gallon a day to keep healthy.
In the morning they try to drink as much as possible in the tent. Once on the trail they use thermos bottles to keep the drinks, well, drinkable.
Yes, the team members constantly harp on each other to drink, drink, drink. And drink the right stuff - not too much coffee or hot chocolate containing caffeine. Certain chemicals in caffeine dehydrate your body. The same goes for many sodas…So next time you feel really thirsty, grab for that water bottle instead, eh…
Measure how much melted ice it takes to make water! Put some ice cubes in a container and record the level of ice on the container. Let the ice melt. How much water is there? Are you surprised at the difference? Now, if you have access to snow do the same with snow. Which of the two leaves you with the most water? Why?
People loose moisture through evaporation from the pores in the skin. When you are hot and begin to sweat, your rate of respiration speeds up in an effort to cool your body. Skin moisture can evaporate rapidly in dry climate, even when you are not sweating. On average, an adult loses about one liter of water a day. When working hard and burning energy that produces heat, that person’s water loss quickens proportionally.
Create a lab that demonstrates aspects of water loss from your body.
- one plastic bag or plastic wrap per student
- masking tape
- paper and pencil
- Cut the plastic bag into a single layered square large enough to fit comfortably around your forearm and tape it securely (but not too tightly) at the top and bottom.
- Wear the plastic over your forearm for at least ten minutes. Meanwhile, in teams of four people take and record your pulse and respiration rates. Then walk up and down a flight of stairs five times. Record your new pulse and respiration rates. Next, run up and down the stairs five times and then record pulse and respiration.
- After the exercise note whether the plastic contains any water condensation released by your skin as it performed respiration and perspiration.
- Take the bag off and feel the moisture on your skin where the plastic has been. Note the moisture level of the skin that was under the plastic as compared to skin exposed to air during the ten minutes.
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