text: Chapter 8
  yellow. If taking B vitamins, Soldiers may have bright yellow urine, not pale, regardless of hydration status.
  Another method for assessing hydration is frequency and volume of urination with a goal of urinating every
  2–3 hours.
  8-66. Excessive loss of electrolytes from sweating can lead to muscle cramping or severe medical problems.
  Being in excellent physical condition helps minimize electrolyte losses, but Soldiers given free access to
  water when exercising in the heat replace only one half to two thirds of their fluid losses. Additionally,
  electrolyte balance may be compromised due to the use of hydration packs which provide only water. Soldiers
  may need to consume snacks, fluids, or both with electrolytes during and after missions or periods of grueling
  and prolonged training. Due to limits to how much sodium and potassium should be provided in sports
  beverages, fluid replacement alone may not be adequate for restoring or maintaining electrolyte balance.
  8-67. Foods that naturally provide sodium and potassium should be selected. Dried fruits are optimal food
  choices for potassium. Even if heat acclimatization has occurred, leaders must understand the importance of
  salt: 200–400 milligrams of sodium can be lost per pound of sweat, along with sodium excreted in the urine.
  Adding salt to foods (1/2 teaspoon provides 1,200 milligrams) or including sodium-rich foods in the diet
  helps retain water and avoid a sodium deficit. Sodium is the most critical electrolyte for maintain fluid
  balance.
  NUTRITION FOR MISSIONS IN THE COLD
  8-68. Exposure to a cold environment seriously challenges the human body. Blood vessels tighten to
  conserve heat and shivering is initiated to generate heat and guard against hypothermia. Side effects of these
  responses are an increase in urine output and an increase in energy metabolism. Therefore, the most important
  nutritional considerations for a cold environments are—
  * Energy intake.
  * Glycogen stores.
  * Fluid status.
  * Vitamin and mineral needs.
  See also ATP 3-90.97 for guidance on nutritional requirements in cold weather and high-altitude
  environments.
  Energy Intake
  8-69. Energy requirements can increase 25–50 percent during cold weather operations as compared to warm
  weather operations. Even mildly cold temperatures (32–57° F) can increase energy requirements 5–10
  percent. Factors that increase caloric intake include—
  * Added exertion due to wearing heavy gear.
  * Shivering, which can increase resting metabolic rate by two to four times the normal level.
  * Increased activity associated with traveling over snow and icy terrain.
  * Increased activity to keep warm.
  8-70. Many studies have shown Soldiers tend to progressively lose weight when conducting two- to three-
  week field exercises in the cold. Because significant weight loss can result in fatigue and declined
  performance, energy intake should meet the increased energy demands.
  8-71. Energy expenditure for Soldiers during periods of physical exertion in the cold may range between
  4,200 to 5,000 calories per day. When temperatures justify high levels of cold-weather protection (for
  example, Extreme Cold Weather Clothing System and the Vapor Barrier Boot), energy requirements may
  increase to approximately 54 calories per kilogram of body weight. Energy needs are higher (approximately
  62 calories per kilogram of body weight) when Soldiers maneuver for prolonged periods (2 hours or more)
  with heavy gear on their feet (for example, snowshoes and skis) over snow- and ice-covered terrain. These
  increased energy requirements do not apply to troops located in cold climates with limited exposure to
  outdoor temperatures.
  8-72. Although carbohydrate consumption is critical, a diet that provides 35 percent of the energy as fat may
  be necessary to match energy needs. Ideally, during cold weather operations, 50–60 percent of energy should