Definition

Dehydration is the abnormal loss of water in the body. Some people never know the detrimental effect of excessive or severe water loss in the human body and it is a topic oftentimes overlooked.

Theoretical frame

Aside from maintaining proper diet and keeping the body fit, it is of vital importance to pay attention in keeping our body properly hydrated at all times. Fact is, around 70 per cent of our body's weight is made up of water. Knowing that, it is very evident that water is a very essential element of the body and proper and adequate hydration is necessary in order for the body to function properly. Water is important for digestion, joint function, healthy skin, and removal of waste products and water is lost from the body thru a number of different ways including loss from urine, loss from humidity, and perspiration. Normally, like in an ordinary day, a person needs to drink significant amount of water to cope up with these routine loss.

There are so many causes of dehydration, one of which is high altitude and because of this, dehydration has become a significant issue in the aviation field. In fact, this "dehydration issue" among pilots can also be considered also as one of the most overlooked issues which can cause significant ill effects. So, in order to assuage this condition and create awareness among pilots, Nina Anderson on her "the effects of dehydration on pilot performance" states that the Federal Aviation Administration (FAA) has recently added pilot dehydration to its list of physiological conditions found in the latest Practical Test Standards—its symptoms, causes, effects and corrective actions.

Proper education of the ill effects of dehydration on pilot performance will have significant impact in lessening and prevention of aircraft incidents and accidents.

There are three stages of dehydration, which are: heat stress, heat exhaustion and heat stroke. Dehydration can be mild, moderate to severe and each stage has its symptoms. Early signs and symptoms include fatigue leading to fainting and may, at very extreme case, lead to coma or even death.

Supporting evidence

Three Stages Of Heat Exhaustion

1. Heat stress (37.5°C to 37.77°C body temperature) reduces:

Performance, dexterity and coordination
Ability to make quick decisions
Alertness
Visual capabilities
Caution

2. Heat exhaustion (38.33°C to 40.55°C body temperature) symptoms:

Fatigue
Nausea/vomiting
Cramps
Rapid breathing
Fainting

3. Heat stroke (above 40.55°C body temperature) symptoms:

Body’s heat control mechanism stops working
Mental confusion
Disorientation
Bizarre behaviour

Aside from low humidity and high altitude, hot cockpits and flight lines also constitute to dehydration. Pilots should be fully aware that good hydration is necessary during flights and should always be one of their major concerns.

The prevention of dehydration in the cockpit is simply keeping yourself hydrated at all times. Having a water bottle and drinking regularly is the best answer to dehydration. The Federal Air Surgeon Bulletin suggests that "drinking cool, 40-degree Fahrenheit (4.45°C) water before feeling thirsty. This will help you stay ahead of the game, keeping you hydrated before the “thirst mechanism” sets in." (the effects of dehydration on pilot performance by Nina Anderson www.longlifecatalogs.com).

The total daily water loss is approximately 2500ml per day. It is recommended that adults drink eight 8-ounce glasses of water each day, but this recommendation depends on age and type of activity. Adults need about 20 oz. of fluid before beginning activity, as well as an additional 10 oz every 15 minutes during activity.

Aside from drinking water, staying away from diuretic drinks like coffee, sodas and teas is suggested because these drinks cause excess urine production. Also, doing strenuous activities before flight should be avoided since it causes excessive body fluid loss.