[MR] h2o

[Laurence Todd]

The gospel, according to TRADOC...

This is the current heat guidelines the the Army Training centers use 

Heat category / heat index / fluid intake quarts per hour 
1                 78-81.9                 3/4
2                 82-84.9                 3/4
3                 85-87.9                 3/4
4                 88-89.9                 3/4 
5                   >90                    1 
 
This is at a moderate work level
 (foot march 2.5 MPH, PT, Individual movement Techniques)

I would suggest at the average fitness level of most reenactors 
1.5 Quarts per hour.

 Urine 
 Sometimes you can use urine color to determine your APPROXIMATE
level of hydration. The clearer your urine the more hydrated you are. 
The darker your urine, the more water you need to drink. NOTE this is 
only a guildline, and should not be taken as a rule because certain 
foods and dietary supplements can impact color. 

so....

1. drink plenty of water BEFORE exposure to heat 

2. Drink smaller quantities of water more frequently

3. Drink extra before exertion.

4. stay in the shade as much as possible.

5. Eat regular meals. 


 However .....

Prevent Hyponatremia

 What is it?. Hyponatremia, or water intoxication, is a condition 
that occurs when there is a lack of salt in the blood, caused by 
inadequate excretion or by excessive water in the circulative blood 
stream. 

 Symptoms. symptoms of hyponatremia include vomiting, seizures, and 
high output of clear urine. In severe cases, you may develop 
confusion, leading to muscle excitability, convulsions, coma, and 
possible death. Symptoms may mimic heat exhaustion. If there is no 
improvement in 30 minutes, then treat as a heat casualty and evacuate. 

 Prevention

1. Drink no more than 1.5 an hour

2. do not exceed 12 quarts per day 

3. drink Sports drink or some type of electrolyte replacement

4. EAT.

(source TRADOC PAM 600-4)