Field training in extreme environments presents special performance nutrition requirements. For one thing, in
heat and cold and at high altitudes you burn more energy than you do in a temperate climate. Therefore, eat
more in extreme environments to fuel your increased energy needs.
Extreme environments create other risks that performance nutrition can help you overcome.
Extreme heat causes your body to heat up faster, which makes you sweat more. That means you need more
water to stay cool.
When you're carrying a load or working in chemical protective clothing, your water needs are even
- Rapid body weight loss
Heat suppresses appetite, especially during the first few days of training. You may not feel like eating
the amount you should to refuel the energy you are burning.
When you don't eat in the heat, you are not getting enough calories. Rapid weight loss reduces your
muscle strength. You also may not be replacing the salt you lose in sweat.
Also, food is a good source of fluids. The result of not eating in hot climates can be fatigue,
dehydration, heat injury, and illness.
- Water- and food-borne illness
Heat encourages growth of germs in food and water. Illness caused by consuming contaminated food and
water can lead to nausea, vomiting, diarrhea, and fever, which increase your risks of dehydration and
When Heat Takes Your Appetite
Here are some foods that might be more appetizing in the heat. They are high in carbohydrates and low in fat. Sometimes eating a snack will get your appetite going, so you'll feel like eating more.
Remember, dehydration takes away your appetite. So keep drinking.
Avoid The Fat
Stay away from high-fat foods in hot weather. Fat is harder to digest and might suppress your appetite even more.
These are not good hot-weather foods.
Hot Climate Performance Nutrition Tactics
- DO follow work/rest cycles
- DO drink regularly, often and before you feel thirsty
- DO drink 10-12 quart canteens of water a day
- DO drink up to 22 quart canteens of water a day if you're wearing chemical protective clothing in extreme heat
- DO monitor urine color. If it is dark yellow or brown instead of pale yellow, drink more
- DO watch for signs of dehydration in yourself and others
- DO eat slightly more than usual
- DO try to eat at least three meals a day
- DO try to eat snacks between meals
- DO eat high-carbohydrate, lowfat foods
- DO purify water. Boil stream water for at least 10 minutes
- DO mix beverage powders in a cup, not in your canteen
- DON'T restrict fluids
- DON'T go on a diet in the field
- DON'T drink unsterile water or ice
- DON'T add beverage powders directly to canteen
- DON'T skip meals