When traveling by air, one should always be conscious of their attire for the trip. Personal comfort, as well as safety, is of concern. Aircraft are typically colder due to the constant operation of air conditioning units to keep the cabin cool (this is due to pressurization systems that without air conditioning, would make the cabin uncomfortably warm). Another consideration is one of safety.
In the event of an accident or incident, fire is of great concern and is a very real threat. Additionally, torn aluminum can become razor sharp. For this reason, long pants and long sleeves should be worn. To guard against burns, garments should be made of natural fibers as opposed to synthetic ones. Cotton is preferable to nylon, and so forth. Natural fibers are flame resistant and will not melt.
Ease of maneuverability in the event of an emergency evacuation should be taken into account as well and items such as high-heels should be avoided as they may tear an escape slide or raft (this is why they tell you heels and hard-soled shoes must be removed during an evacuation).
Finally, comfort should be a major consideration as being in an aircraft accident is exceedingly rare. Be sure to wear items that give yourself plenty of breathing room and that you will be able to relax comfortably wearing. After all, you won’t be able to sleep if you aren’t comfortable. Be sure to allow for ample circulation throughout your extremities and torso.
Remember to dress loose, comfortable, and keep yourself covered using clothing made of natural fibers. You will have a much better flight!