There may be doctors on board, but if they're American, they likely can't help you

In-flight medical emergencies happen to the tune of 44,ooo times each year. One of out every 604 flights will trade out the usual crying babies for an actual harrowing emergency, according to a new report from The New England Journal of Medicine.

The most numerous of these emergencies, 37%, involve syncope, fainting brought on by dehydration, which is exacerbated by the dry air in the cabin. Heart attacks, on the other hand, make up just .3% of medical incidents on flights, but 87% of in-flight deaths.

More surprising than the sheer number of medical emergencies taking place up in the clouds each year is the number of flights that do end up having a doctor on board. An estimated 3 out of 4 emergencies occur while a medical professional is also flying. But a doctor's presence on board doesn't mean that doctor can actually help.

Doctors from Australia and many European nations are mandated by law to perform life-saving assistance if needed, but American doctors face no such requirement. In fact, American doctors must defer to their insurance policies, which may actually prohibit them from contributing care. They also have to consider how their insurance interacts with the laws of both the country directly (far) below the plane at the moment of crisis and the laws of the nation the ailing passenger hails from. To say that these factors form a tangled web of paralyzing culpability is an understatement.

Further, planes face no requirement to land in the event of a medical emergency, with good reason. Weather conditions, fuel levels and actual vacancy on an unsuspecting airstrip can all prevent planes from touching down in time to save a life. Even in the event of a landing, there is no guarantee that the proper resources necessary to give life-saving care will be available. The sole decision-making power to land a plane lies with the captain.

Planes are equipped with first aid kits, which are typically more inclusive than you might think, with syringes, a stethoscope, and various other medical instruments, in addition to staples like painkillers and gauze. Flight attendants are also trained in CPR and the use of defibrillators.

In light of all that can go wrong while trapped in the sky, though, passengers in uncertain health should definitely use caution.