[Therapy of jet lag]

After transmeridian flights, disturbances of the circadian rhythm and sleep occur due to the desynchronization between the body clock and external zeitgebers. Under normal circumstances, these disturbances are not pathological and disappear within a few days. However, they impair well-being and lead to significant changes in performance and vigilance. These effects are of particular importance for tasks and operations which require enhanced attention and alertness. Some of the acute symptoms of jet-lag can be reduced and shortened by appropriate countermeasures. The application of these therapies is practicable and has been successfully incorporated in clinical measures.