Many aircraft emergencies involve the loss of power and, consequently, the failure of cabin lighting; smoke can also dramatically reduce the ability to see one’s surroundings. So it’s difficult to over- emphasize the importance of carrying your own source of quality illumination, in the form of a powerful, reliable, rugged, long-lasting, waterproof flashlight (torch).
Such a light is highly useful in a variety of travel situations: navigating dark streets, late night reading, finding your way to the toilet, exploring lava tubes in Hawai'i, and locating items in an overhead compartment on a night flight. But nowhere is it more likely to save your life than in the event of a plane crash (or hotel fire).
Fortunately, thanks to modern LED technology, this critical survival tool can also be surprisingly small and lightweight. Expect to spend around $50 for a top-of-the line light, and expect to be amazed at its capabilities. Ensure that (1) its batteries are reasonably fresh (for this reason, it’s better to select one that uses ubiquitous AA batteries, rather than exotic photo/watch batteries), and (2) you keep it handy: there’s no point in having a state-of-the-art survival tool buried somewhere in your luggage.
At night, consider turning off your at-seat light(s) during the “full alert” periods; this allows your eyes to pre-adjust to the darkness in case of an emergency. Most aircraft dim the main cabin lights for nighttime takeoffs and landings; simply take this a step further by turning yours off as well.