It is not a hit and miss thing. A great amount of research goes into discovering passenger preferences and how they impact on loyalty and comeback. Come back passengers are an airline’s bread and butter and it is not just first and business upper crust who are given incentive but also economy passengers whose comfort in relatively confined conditions is now a constant factor in corporate decision-making. Ambience is the word and it is a key feature of the passenger cabin, as you enter it and the first impression the cabin makes on you. it ought to have a relaxed, welcoming aura about it. Warm colors, soothing music, ample cushioned seats and a designer décor, all contrive to make you enjoy your journey. You’ll be surprised how a stake smell, that rancid toilet stench and tattered seats and rusted cabins that shriek old age can put off a passenger. You want to run back and say, sorry get me out of here.

Throughout the flight, the ambient temperature will be in the comfort zone: Around 21 to 23 degrees C, may be a little less or more. But you are not expected to freeze and if you think you may do so, ask for a blanket. Amazing how many passengers are afraid to demand a blanket when the control of the cabin temperature drops and you are shivering in your seat. Switch off the nozzle on to for a start. In fact, the clothing you choose to wear for the flight, should reflect weather conditions at your destination so don’t get off in plus 90 degrees with a sweater and an overcoat.

The humidity will rarely be over 20 to 25 percent, and this could be a source of trouble for some ailments, specially of the upper respiratory tract, and those with dry eyes. Carry eye drops and skin moisturiser.This is good for males so don’t be shy.  

The ambient pressure in the cabin will be varying from sea level, to that which pertains at about 6,000 feet altitude above mean sea level. This  does not in anyway, represent a physiological challenge to a healthy body, but for those with specific lung diseases, it may warrant supplemental oxygen…factors that patients also do not want to confess to in case the airlines refuses them the right to board. This is another major aspect and as the issue of medical attention manifests itself there will be a further complication coming out of offloading passengers whose medical condition may daunt the airline from giving them passage for fear of legal problems on the way.

With new and exotic viruses floating about and aircraft having no boundaries so to speak the cabin air and the "infection" liability of 350 people breathing the same air is tangible.

There are often reports in the lay press about cosmic or solar radiation and its effects on the frequent flyer passenger. All available evidence to-date points to a much ado about nothing type of reaction, though airline pilots  have been the focus of a  more defined probing….with still nothing significant emerging.

Ozone is nowadays, best defined as a contaminant in the cabin atmospheric composition, and since it was first found out to be responsible for some niggling nose and throat problems a couple of decades ago, countermeasures have  brought ozone in the cabin to very safe levels.

What you should concern yourself with is Deep Vein Thrombosis if you are on a long flight. Take a walk every two hours, up and down the cabin,stretch like a cat, it is good for you. 

Jet lag, cramped confines, dry air, air conditioned recycling of germs and viruses, proximity to affected passengers, these are all grey areas. Not much has been stated about fear of flying which is whole new game in itself and has reactions to many conditions including blood pressure, ischemic heart disease and nervous disorders. Ailments like asthma, respiratory complications, allergies, back problems, colds and coughs and migraine can be triggered by stimuli found in flying.

It won’t be long before the industry gets an act together on the subject of medicine in the air. In the interim be sure there will be much more about this issue in the future.