[at-l] Hydration in Hot and Cold Environments.

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This information is from the U.S. Army. Change Soldiers to Backpacker.

Wildbill

HOT ENVIRONMENT
Maintain Adequate Hydration 
1. Adjust fluid intake and work-rest cycles as temperature varies. 
Soldiers working in warm weather require approximately 4 to 6 quarts of 
water per day and need more water as physical work and temperatures 
increase. Military personnel working in hot environments require 10 to 
12 quarts of water per day . Under extreme heat, especially in an 
environment in which soldiers wear chemical protective clothing, water 
requirements may increase to as much as 28 quarts per day (7 gallons). 
However, 18 quarts is about the maximum amount of water that individuals 
can drink and the body absorb in 18 waking hours. It is imperative that 
commanders consider the amount of water necessary at different 
environmental temperatures to support the corresponding work-rest 
schedules. 
2. Enforce routine water consumption. Soldiers need to drink even when 
they are not thirsty. It is best to plan and enforce a schedule for 
drinking. A suitable drinking schedule, for an average-sized soldier 
working in moderate heat, is to drink 1 liter of water in the morning, 1 
liter at each of three meals, and routinely drink small amounts (2 cups 
every 30 min) throughout the work period. Remember, it is much better to 
drink small amounts of water frequently than to drink large amounts 
occasionally. Following a schedule may seem tedious, but in the long run 
it helps soldiers to drink more. This reduces the likelihood of soldiers 
becoming heat casualties, in addition to preserving their physical 
performance capabilities. 
3. Provide palatable water. Plain, cool (60-70°F; 15-21°C) water is the 
best beverage for maintaining adequate hydration status since the 
stomach easily empties it and absorbs it quickly into the rest of the 
body; however, individuals voluntarily consume flavored, cool water in 
larger amounts than plain, warm water. Nevertheless, almost any type of 
beverage consumed helps soldiers meet their water requirement (e.g., 
koolaid, juice, decaffeinated coffee, tea, soft drinks, lemonade, soups, 
milk). Cool beverages by shading, insulating, and camouflaging water 
buffaloes or by using small mobile chillers. Drinking alcoholic or 
caffeinated beverages may increase urination and the tendency for 
dehydration. 
4. Monitor soldiers for signs of dehydration. 
a. Monitor the color and volume of the urine of soldiers. Dark yellow or 
brown urine and less than normal amounts of urine indicate dehydration. 
Have soldiers drink until their urine turns pale yellow in color. 

b. Monitor weight loss if possible. Weight loss is a good indicator of 
dehydration. Even mild dehydration (indicated by a loss of 2% of body 
weight) affects an individual's physical performance, mood, and the 
desire to eat, as well as increases the risk of heat injury or illness. 

c. Have soldiers monitor themselves for signs of dehydration or illness. 
Encourage the use of the "buddy system" to help detect signs of 
dehydration and illness in others
. 
The above information came from the:
NUTRITIONAL ADVICE FOR MILITARY OPERATIONS IN A HOT ENVIRONMENT
***********************************************************

COLD ENVIRONMENT
Maintain Adequate Hydration 
1. Soldiers must drink even when they are not thirsty. Leaders should 
establish a program of regularly scheduled, enforced drinking. 
a) Soldiers should drink at least five to six canteens of water each day 
if active. Sedentary activities in the cold require about four canteens 
of water per day. 

b) Schedule drinking at hourly intervals. One half canteen consumed each 
hour results in four canteens of water consumed over an 8 hour day. 
This, in addition to drinking one half canteen with meals and with an 
evening snack ensures consumption of the recommended quantity of fluids 
each day. 
2. If a soldier's urine shows dark yellow it may indicate that fluid 
intake is not adequate; the soldier should increase the quantity of 
fluids drink until urine turns pale yellow. 
3. Eating snow or ice for moisture is inefficient, may irritate the 
lining of the mouth, and may lower body temperature. It is better to 
melt snow or ice and purify it before consuming. 
4. A cup of hot coffee or tea is a welcome "pick-me-up" in the cold, but 
excessive caffeine consumption leads to frequent urination, dehydration, 
and difficulty sleeping, depending upon individual tolerances. Cocoa is 
generally a better beverage than coffee in the cold. Cocoa is much lower 
in caffeine, high in needed carbohydrate, and is warming. 
5. Consuming alcoholic beverages is detrimental in the harsh cold. 
Drinking alcoholic beverages accelerates body heat loss (by bringing 
more blood to the surface of the skin) and impairs judgement. 
6. Avoid consuming excess salt (more than that normally provided in the 
military rations). Excess salt increases the body's water requirements 
since a person must drink more water to excrete it. Excess salt 
consumption without adequate water intake leads to or aggravates 
dehydration. 
The above information came from the:
NUTRITIONAL ADVICE FOR OPERATIONS IN A COLD ENVIRONMENT
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If you would like to see the whole manuals, they are on the site. Click on
Deployment Manuals.
 <A HREF="http://www.usariem.army.mil/">USARIEM</A> 

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