Cold-Weather Operations:
Food and Water

Four standard MREs per day must be eaten to supply a Soldier the necessary calories during cold weather, if no other rations are provided. A general recommendation for Soldiers participating in cold-weather operations is to consume about a half a quart (half a canteen) of water with breakfast, lunch, dinner and before going to sleep at night, with an additional half quart drunk every hour during the workday (more if the work is strenuous enough to cause the individual to sweat) for a total of at least 5-6 quarts of water per day. "Prevention of cold injuries is the responsibility of commanders at all levels."

Although warm clothing and proper shelter are the first line of defense in protecting against the effects of cold weather, adequate food and water consumption are next in importance. Food and water requirements of Soldiers are high during cold-weather operations, and the effects of dehydration and inadequate diet are as serious as in hot climates.

Understanding the Problems:

1. Soldiers often become dehydrated during cold-weather operations. Dehydration increases susceptibility to cold injuries and reduces work capacity, appetite, alertness, and can lead to other medical problems such as constipation, kidney disorders, and urinary infections.

2. The body's requirement for water is high during cold-weather operations. In cold weather, sweating can contribute to body water losses. Heavy clothing can cause overheating, especially during heavy work, which in turn leads to sweating. In cold dry conditions, sweat may evaporate readily without the individual sensing it. Unless water intake exceeds body water losses, dehydration will result.

3. Soldiers reduce their fluid intake during all field operations, but especially during cold weather. Because field rations contain less water than garrison food, Soldiers take in less water with the food they eat, and they usually do not drink enough to compensate. Most people do not feel thirsty until they are already significantly dehydrated, and thirst may even less noticeable in cold as in hot weather. When weather is particularly cold and/or rainy, many Soldiers purposely allow themselves to become dehydrated to avoid having to leave comfortable shelter to urinate outdoors. When temperatures are extremely low, water in canteens and bulk supply containers may freeze, restricting water availability.

4. Water consumption requirements are more difficult to predict for cold-weather operations than hot, because the effects of the environment are greatly modified by an individual's own bodily responses, the workload, and the amount of clothing worn. This individual variability affects the amount of water required to maintain proper hydration.

5. Caloric requirements of Soldiers are 25 to 50% higher during cold-weather operations than in warm or hot weather. Soldiers expend more energy during cold weather due to wearing heavy cold-weather gear and the increased effort required for working or walking in snow or mud or for preparing positions in frozen ground. The body uses more calories keeping itself warm when the weather is cold, which also contributes to the increased energy requirement.

Various measures exist to cope with food and water problems:

• Ensure that Soldiers in the field receive adequate amounts of hot rations. Four standard MREs per day must be eaten to supply a Soldier the necessary calories during cold weather, if no other rations are provided.

• Soldiers must drink even when they are not thirsty. Leaders should establish a program of regularly scheduled enforced drinking. A general recommendation for Soldiers participating in cold-weather operations is to consume about half a quart (half a canteen) of water with breakfast, lunch, dinner, and before going to sleep at night, with an additional half quart drunk every hour during the workday (more if the work is strenuous enough to cause the individual to sweat) for a total of at least 5-6 quarts per day.

• Soldiers should be taught that the lighter the urine color, the better hydrated, and that dark yellow urine is a sure indicator that fluid consumption should be increased.

• In extremely cold weather (below -10°F), standard issue canteens and the 5 gallon metal water containers can freeze. Spare canteens should be kept inside heated vehicles or tents. At least one full 5 gallon water container per squad should be kept thawed at all times.