Among military aviation missions, those involving rapid deployment and night operations are the most disruptive to sleep and performance. Mission objectives often require quick response, rapid travel across many time zones, and immediate rotation of work schedules from daylight to either nighttime or early morning duty hours. These manifest themselves in varying degrees of sleep loss, fatigue, alertness degradation, digestive disorders, stress, and performance degradation. The melatonin group exhibited substantially fewer errors than the placebo group in various types of task testing.
Hyperventilation is the basis of adaptation to high altitude.
Homesickness is defined as a preoccupation with a longing for the home environment among people who have left home. Homesickness also occurs among travelers, migrant workers, and refugees. Distance from home is less important than the length of stay and the absence of acquaintances. There is a firm association between homesickness and rigidity, neuroticism, and lack of self confidence. Often the home environment is idealized.