With longer international flights, concerns are raised about the transmission of more serious communicable diseases among travelers. A 1996 study published by the New England Journal of Medicine found evidence that tuberculosis can be transmitted between passengers and that the risk of transmission increased with duration of in-flight exposure. However, the study did note that the number of people flying with tuberculosis is probably very low, as little as one in 9 million, suggesting a very low risk of exposure to flight crews and passengers. Use a saline spray to keep the nasal membranes moist. Eating and drinking increases the heart's blood output, sustaining the flow of oxygen to the brain and heart.
Hunger is a risk factor for an in-flight emergency.
People need to know it is easy to fall into hypoxia if they don't eat and drink before boarding a plane. Pneumococcal and influenza vaccinations are appropriate. Supplemental oxygen is available on US airlines, but must be ordered in advance. Travelers are not permitted to use their own oxygen tanks in flight. In general, supplemental oxygen should be considered if the arterial PaO2 is likely to be 50 mm or less during flight.