The crossing of several time zones disrupts the sleeping and waking cycle, producing jet-lag. The time needed for complete readjustment depends on the number of zones crossed and may be a week or longer. It is advisable to schedule some periods of rest in the first few days after arrival. It may also be useful to take a short-acting sleeping pill for the first few nights after the journey.
Travel sickness is very rare in the case of air travel.
Travelsickness drugs and other medicines that need to be taken regularly should be carried as hand baggage rather than as registered luggage.