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The Effects of Dehydration (Part 1)
The thirst mechanism (dry mouth) that alerts you to the need to drink often does not “kick-in” until up to 2% of your body weight has been lost. This initial stage of dehydration will cause fatigue, irritation, nausea or severe headache. Dehydration will often be overlooked as the cause.
Both the body and brain need to be hydrated to function properly. A loss of just 5% body weight due to dehydration can cause a 25% loss in physical and mental capacity. Most people who loose 10% of their body-weight due to dehydration will require medical assistance to recover. Death occurs with a 15% to 25% weight loss.
People suffering the effects of dehydration need to replace lost electrolytes. Oral re-hydration solutions are available as a ready-mix in many pharmacies, especially in tropical countries. Powdered sports drinks such as Gatorade ™ work best if mixed half-strength. To make your own oral hydration solution, mix a teaspoon of table salt into one liter of clean water. To this add eight level teaspoons of sugar. Any sugar that you have available is acceptable (honey, molasses, corn syrup, brown sugar etc.).
Facing The Worst Case Scenario
If you find yourself in a situation where you will be without water for more than 24 hours you should drink whatever fresh water you have available as you need it and find more. YOUR WATER SUPPLY HAS BECOME YOUR TOP PRIORITY AND YOU CANNOT ESCAPE THE FACT – AT THIS POINT YOU MUST FIND WATER.
Your body’s need for water is second only to its need for oxygen. You should not attempt to ration drinking water, especially to children. You must drink what your body needs, when your body needs it. The effects of dehydration will greatly decrease your ability to deal with the situation at hand - your dire need to find more water. Once you have begun to dehydrate, the tiny amounts of water allowed by rationing do NOTHING to reverse the slide, and at best slow it by an imperceptible degree.
For instance, a 150-pound man who realizes by his dry mouth and discomfort that he is thirsty has already lost 2% of his body weight. That translates to 3 pounds or about a quart/liter of water. By the time he reaches a 5% weight loss he has lost 7.5 pounds or about equivalent of a 2-liter bottle. By allowing himself a “Hollywood water ration” of several capfuls an hour, or some such nonsense, he is doing ABSOLUTELY NOTHING to reverse his slide into dehydration. His physical activity and the environmental conditions are extracting water from his system at a far greater rate than he is replacing it. In a short time he will drop to 10% weight loss, or 15 pounds, more than two 2 liter bottles.
If water is not available you must conserve the water you still have INSIDE YOUR BODY. You cannot control your waste elimination; your body will devote water to this task automatically. Your body will use water to digest food and will take that water from your body tissues if you do not drink before a meal. If you have no water, you should not eat food, especially protein (meat). The digestion of meat uses far more water than the digestion of carbohydrates (sugars and starches). If you eat nothing your body will be able to eliminate waste with the water it would otherwise have to devote to digestion.
If you ration anything, you should ration perspiration by keeping in the shade and limiting physical activity until it is cooler. Perspiration is the number one enemy of a dehydrated person and the only route of water loss that you can directly control. By limiting food intake and physical activity you can conserve your strength to search for water after it cools off in the evening.
If you must drink untreated water, let it stand in a container for an hour to allow sediment to settle. Filter the water through a T-shirt, clean handkerchief, or charcoal to remove as many contaminants as possible. Black lumps of charcoal left over from a fire can be used to filter water only if they are free of white ash. Ashes when mixed with water will produce lye.
The incubation period of any water-born illness is probably longer than your “survival ordeal” will last. Once you are rescued any illness you may have contracted can then be treated.
Under no circumstances should you drink seawater or urine. In order to eliminate seawater from the stomach the body first reduces the salt concentration of the seawater by robbing water from body tissues. This greatly compounds the effects of dehydration. With a minimum of planning, however, such a situation should never need to occur.
EMERGENCY COLLECTION OF DRINKING WATER
These “High Yield / Low Effort” water collection methods produce enough water to live on without a great price in perspiration. The more complicated methods, such as digging pits or making solar stills tend to produce little more water than the sweat they cost.
Water from flowing or standing surface sources: streams, puddles, lakes, rivers, ponds, or swamps
This seems obvious, but people often pass up water sources because they don’t “look good enough to drink”. Water from the worst looking algae laden frog pond can be made biologically safe to drink. In fact, the presence of small water creatures is a good indicator that the water is free of toxic chemicals. Unless the water source has some type of industrial or agricultural pollution you should make use of it, treating the water as best you can. NOTE: Floodwaters are highly contaminated with raw sewage and other waste and can only be made pure by distillation.
Collection of rainwater
Rainwater that falls directly from the sky to a clean collector/container is pure water and does not need to be treated. If the rainwater is falling through a canopy of leaves, or from a rooftop it will need to be filtered and treated. Use a poncho or plastic bag to collect and direct water into a container. Allow a clean towel or shirt to soak up falling rain and wring it into a container.
If you are caught in an open boat at sea, rain collection is essential. Your clothing and other rain collection surfaces will most likely collect a high concentration of sea salt during dry conditions due to the evaporation of sea-spray. This excess sea salt needs to be washed away with ordinary seawater before you use that article to collect fresh rainwater. Once an article of clothing has been washed with seawater and wrung out its salt content is no greater than the surrounding sea. As soon as fresh rainwater hits it the resulting brackish water will have less salinity than seawater. In short order the rain will wash the article of clothing until only fresh water is being collected. If you do not wash the clothing in fresh seawater first you will simply dissolve the high salt concentration into your fresh rainwater, essentially collecting seawater.
Melting snow over a fire
Fill a net bag, shirt, or other cloth sack with loose snow and hang it next to your fire where it will be out of the smoke but close to the radiant heat. Chunks of solid ice contain more water than snow and will produce more melt water. Collect the dripping water in a container placed below.
Dew collection
Often in dry areas heavy dew will form in the early morning hours. Pass a towel or t-shirt over wet vegetation or rocks until it is sopping wet then wring it out into a container. This method can produce copious amounts of water if the dew is heavy but the water is often muddy or cloudy. Whatever dust had settled on the leaves will be sopped up as well. This water should be filtered, boiled, or treated chemically.
Taking water from plants
Many vines contain a great deal of water. They can be cut to allow the water to drain from a hanging section or to drip into a container. Never drink white or milky sap. The trunk of a banana tree will continue to pump water for a day or so after being cut. Hollow out the top of the stump and it will fill with water. Likewise sections of bamboo often contain large amounts of water.
The thirst mechanism (dry mouth) that alerts you to the need to drink often does not “kick-in” until up to 2% of your body weight has been lost. This initial stage of dehydration will cause fatigue, irritation, nausea or severe headache. Dehydration will often be overlooked as the cause.
Both the body and brain need to be hydrated to function properly. A loss of just 5% body weight due to dehydration can cause a 25% loss in physical and mental capacity. Most people who loose 10% of their body-weight due to dehydration will require medical assistance to recover. Death occurs with a 15% to 25% weight loss.
People suffering the effects of dehydration need to replace lost electrolytes. Oral re-hydration solutions are available as a ready-mix in many pharmacies, especially in tropical countries. Powdered sports drinks such as Gatorade ™ work best if mixed half-strength. To make your own oral hydration solution, mix a teaspoon of table salt into one liter of clean water. To this add eight level teaspoons of sugar. Any sugar that you have available is acceptable (honey, molasses, corn syrup, brown sugar etc.).
Facing The Worst Case Scenario
If you find yourself in a situation where you will be without water for more than 24 hours you should drink whatever fresh water you have available as you need it and find more. YOUR WATER SUPPLY HAS BECOME YOUR TOP PRIORITY AND YOU CANNOT ESCAPE THE FACT – AT THIS POINT YOU MUST FIND WATER.
Your body’s need for water is second only to its need for oxygen. You should not attempt to ration drinking water, especially to children. You must drink what your body needs, when your body needs it. The effects of dehydration will greatly decrease your ability to deal with the situation at hand - your dire need to find more water. Once you have begun to dehydrate, the tiny amounts of water allowed by rationing do NOTHING to reverse the slide, and at best slow it by an imperceptible degree.
For instance, a 150-pound man who realizes by his dry mouth and discomfort that he is thirsty has already lost 2% of his body weight. That translates to 3 pounds or about a quart/liter of water. By the time he reaches a 5% weight loss he has lost 7.5 pounds or about equivalent of a 2-liter bottle. By allowing himself a “Hollywood water ration” of several capfuls an hour, or some such nonsense, he is doing ABSOLUTELY NOTHING to reverse his slide into dehydration. His physical activity and the environmental conditions are extracting water from his system at a far greater rate than he is replacing it. In a short time he will drop to 10% weight loss, or 15 pounds, more than two 2 liter bottles.
If water is not available you must conserve the water you still have INSIDE YOUR BODY. You cannot control your waste elimination; your body will devote water to this task automatically. Your body will use water to digest food and will take that water from your body tissues if you do not drink before a meal. If you have no water, you should not eat food, especially protein (meat). The digestion of meat uses far more water than the digestion of carbohydrates (sugars and starches). If you eat nothing your body will be able to eliminate waste with the water it would otherwise have to devote to digestion.
If you ration anything, you should ration perspiration by keeping in the shade and limiting physical activity until it is cooler. Perspiration is the number one enemy of a dehydrated person and the only route of water loss that you can directly control. By limiting food intake and physical activity you can conserve your strength to search for water after it cools off in the evening.
If you must drink untreated water, let it stand in a container for an hour to allow sediment to settle. Filter the water through a T-shirt, clean handkerchief, or charcoal to remove as many contaminants as possible. Black lumps of charcoal left over from a fire can be used to filter water only if they are free of white ash. Ashes when mixed with water will produce lye.
The incubation period of any water-born illness is probably longer than your “survival ordeal” will last. Once you are rescued any illness you may have contracted can then be treated.
Under no circumstances should you drink seawater or urine. In order to eliminate seawater from the stomach the body first reduces the salt concentration of the seawater by robbing water from body tissues. This greatly compounds the effects of dehydration. With a minimum of planning, however, such a situation should never need to occur.
EMERGENCY COLLECTION OF DRINKING WATER
These “High Yield / Low Effort” water collection methods produce enough water to live on without a great price in perspiration. The more complicated methods, such as digging pits or making solar stills tend to produce little more water than the sweat they cost.
Water from flowing or standing surface sources: streams, puddles, lakes, rivers, ponds, or swamps
This seems obvious, but people often pass up water sources because they don’t “look good enough to drink”. Water from the worst looking algae laden frog pond can be made biologically safe to drink. In fact, the presence of small water creatures is a good indicator that the water is free of toxic chemicals. Unless the water source has some type of industrial or agricultural pollution you should make use of it, treating the water as best you can. NOTE: Floodwaters are highly contaminated with raw sewage and other waste and can only be made pure by distillation.
Collection of rainwater
Rainwater that falls directly from the sky to a clean collector/container is pure water and does not need to be treated. If the rainwater is falling through a canopy of leaves, or from a rooftop it will need to be filtered and treated. Use a poncho or plastic bag to collect and direct water into a container. Allow a clean towel or shirt to soak up falling rain and wring it into a container.
If you are caught in an open boat at sea, rain collection is essential. Your clothing and other rain collection surfaces will most likely collect a high concentration of sea salt during dry conditions due to the evaporation of sea-spray. This excess sea salt needs to be washed away with ordinary seawater before you use that article to collect fresh rainwater. Once an article of clothing has been washed with seawater and wrung out its salt content is no greater than the surrounding sea. As soon as fresh rainwater hits it the resulting brackish water will have less salinity than seawater. In short order the rain will wash the article of clothing until only fresh water is being collected. If you do not wash the clothing in fresh seawater first you will simply dissolve the high salt concentration into your fresh rainwater, essentially collecting seawater.
Melting snow over a fire
Fill a net bag, shirt, or other cloth sack with loose snow and hang it next to your fire where it will be out of the smoke but close to the radiant heat. Chunks of solid ice contain more water than snow and will produce more melt water. Collect the dripping water in a container placed below.
Dew collection
Often in dry areas heavy dew will form in the early morning hours. Pass a towel or t-shirt over wet vegetation or rocks until it is sopping wet then wring it out into a container. This method can produce copious amounts of water if the dew is heavy but the water is often muddy or cloudy. Whatever dust had settled on the leaves will be sopped up as well. This water should be filtered, boiled, or treated chemically.
Taking water from plants
Many vines contain a great deal of water. They can be cut to allow the water to drain from a hanging section or to drip into a container. Never drink white or milky sap. The trunk of a banana tree will continue to pump water for a day or so after being cut. Hollow out the top of the stump and it will fill with water. Likewise sections of bamboo often contain large amounts of water.
can be used as a cost effective means to chemically disinfect and preserve it. Use of chlorine bleach allows you to duplicate the process used in many municipal water treatment systems in the US, only on a much smaller scale. Any brand of chlorine bleach will do as long as you use only pure, unscented bleach. 
-- Bring melted snow/ice to a good rolling boil before you drink (drinking hot fluids is good against hypothermia anyways).