The opening chapter of a new story involves a wandering swordsman in the desert, and I want to portray his dehydration in a convincing manner. I know a person can survive without water for three days, but how long before dehydration becomes functionally debilitating? Could someone go a day without water and still be able to travel by foot? Thanks in advance.
That whole "survive for three days" is based on very specific conditions. Depending on his level of exertion, the heat of the desert, his body weight, and how recently he's had any food or water, the desert could kill him in as little as six hours. Here's a handy guide about that http://www.wikihow.com/Stay-Hydrated-in-a-Desert Dehydration's main symptom is a steady increase in lethargy. A headache is usually the first sign of a problem. Gradually his body is going to start shutting down, he'll get steadily weaker and weaker. His skin will dry out, his eyes will really start to hurt, and his heart rate is going to sky rocket. At that point just water alone isn't going to help, his sweat has leached a dozen chemicals out of his body and they all need to be replaced. At the end is delirium and hallucinations. Most recovery operations in the desert you find people who look like they just decided to sit down and rest for a little bit, got comfortable and died. It's a little less dramatic than hypothermia, but still kills a couple of thousand people a year (can't find good figures, sorry).
Wowie, thanks! Yeah, this is really helpful, and I will be referring back to that WikiHow while I write. It actually also helped answer a follow-up question, which was going to be whether finding a surprise water source later that night would "make up" for the previous day.
Had a similar experience and it is just as above Lethargy came in like it would from a marathon and muscles hurt the same. Gravity increased by 20%. I didn't notice thirst until I did and from there to dirty puddle was very fast. I still Love that dirty puddle with all my heart to this day. Poo and bits of dead sheep don't factor. Reckon if you were e.g. suddenly right now travelling by foot in central Australia, you'd be hitting that puddle by lunch.
The only issue with drinking the dirty water is that if you end up with giardia you're going to end up much worse than before. If your guy has a water bottle a piece of cloth and some mud, he can get most of the shit out of the water (which is good) but not the bacteria (which is bad). The best thing he could do would be find a way to boil the water before he drinks it. But in a survival situation, if he knows he'll be getting out of the desert soon, he might just drink the water, and let the diarrhea hit him when he's someplace he can afford to loose the fluids.
"Well I love that dirty water. Oh, Boston, you’re my home,’’ Dick Dodd of the Standells sang in 1966’s “Dirty Water.” This song dedicated to Frankee_thecat. Good advice Jack Asher.
Electrolytes are going to depend on the cause of dehydration. If you have vomiting and diarrhea you usually get a serious loss of potassium. But if you don't have water to drink and you are perspiring in the heat, your sweat glands, just like your kidneys have the ability to retain sodium. And if you are dehydrated, both kidneys and sweat glands will also conserve water. Sweat rate and sodium loss during work in the heat The mechanism of regulation (technical article) Essentially as the water is excreted along the sweat gland, sodium is reabsorbed (or not) before the water reaches the skin surface. None of this, however, negates the advice to consume salt when hiking in the heat.