We need it:
- to digest food and absorb nutrients.
- to maintain proper muscle tone.
- to supply oxygen and nutrients to our cells.
- to rid our body of wastes.
- to cool ourselves.
- to protect against illness (lymph).
- and to lubricates and cushions joints.
When it comes to survival
your first thought should be clean drinkable water.
The smart people at the United States National Research
Council tell us that total water intake, including water in foods (20% of water
comes from your food. The best hydration foods being berries and fruits while
meat and salty things are going to have an adverse effect on your water
levels.), should be 3.7L for men and 2.7L for women. The folks over at the US
Institute of Medicine have a little different take and say men only need 3L and
women 2.2L unless they are pregnant then it is 2.4L and if they are
breastfeeding a whole 3L.
We lose water when we sweat, pee, poop and believe it or not
breathe (water vapor, you know like when you fog up your sunglasses or that dvd
to clean it?).
I found the following table at survivaltopics.com and it
seems to be a pretty splendid breakdown of survival water rationing. Some
people have gone 8 to 10 days without water and lived to tell the tale but
let’s not test that shall we?
Max Daily
Temperature
|
No Water
|
1 Quart
|
2 Quarts
|
4 Quarts
|
10 Quarts
|
20 Quarts
|
120 F
|
2 days
|
2 days
|
2 days
|
2½ days
|
3 days
|
4½ days
|
110 F
|
3 days
|
3 days
|
3½ days
|
4 days
|
5 days
|
7 days
|
100 F
|
5 days
|
5½ days
|
6 days
|
7 days
|
9½ days
|
13½ days
|
90 F
|
7 days
|
8 days
|
9 days
|
10½ days
|
15 days
|
23 days
|
80 F
|
9 days
|
10 days
|
11 days
|
13 days
|
19 days
|
29 days
|
70 F
|
10 days
|
11 days
|
12 days
|
14 days
|
20½ days
|
32 days
|
60 F
|
10 days
|
11 days
|
12 days
|
14 days
|
21 days
|
32 days
|
50 F
|
10 days
|
11 days
|
12 days
|
14½ days
|
21 days
|
32 days
|
If you lose 2.5% of your body weight through water loss you
are going to lose 25% efficiency. In other words, a 175lb guy only needs to
lose 2L of water to be dangerously dehydrated. And if you think about it when
you take a jog on a hot day you lose about 500ml to sweat and then you go to
the bathroom and another 800ml is going down the drain. That brings you pretty
close to your limit.
Signs of dehydration start small with things like being
thirsty, dark urine or less urine, headache, lack of sweating and dry lips or
skin. Things get a little more serious when you start to feel tired or weak,
dizzy, confused and start passing out. At this point you have issues and the
sunken eyes, shriveled and dry skin, low blood pressure, rapid heartbeat and
rapid breathing make an appearance. If this goes on you are in danger of
heatstroke, cerebral edema (brain swelling), seizures, hypovolemic shock (not
enough blood, pressure or oxygen), kidney failure, coma and death. (queue scary
doom music)
To prevent all of that, look for water early in your
survival situation. Take note: 96.5% of water is found in the ocean, 1.7% is
groundwater, 1.7% is frozen in glaciers, .001% is floating around the sky as
clouds. Of all that only 2.5% of the world’s water is fresh enough to drink and
most of it is frozen or underground. So if you are lost you will be looking for
the worlds .3% of freshwater available in lakes, ponds, rivers or falling from
the sky.
But just because it is wet doesn’t mean you should drink it.
Water is contaminated in many ways. Impurities can be removed by screening,
sedimentation, filtration, chlorination or irradiation. But we will go into
that some other day.
Arrivederci