Eric LaMarque survived being stranded in the backcountry around Mammoth Mountain. Aron Ralston survived 127 hours of hell after becoming trapped under a boulder. We’re betting that these and other famous survivalists would recommend LED flashlights for emergencies, for the reasons listed below:
Long Run Times and Bulb Life
Yesterday’s flashlights contained incandescent bulbs, which provide light by way of a glowing-hot filament. This design naturally loses a lot of power to heat. In contrast, LED bulbs provide light via light emitting diodes that naturally release light when charged particles change energy states. In this circumstance, very little energy is lost to heat.
Indeed, many LED flashlights can run on the same set of batteries for hundreds of hours. Moreover, a single LED bulb may last for hundreds of thousands of hours. In contrast, most incandescent bulbs provide between 750 and 1000 hours of light.
However, even for LED bulbs, energy efficiency declines at high levels of light output. Therefore, you can probably achieve the best efficiency by choosing to run your LED flashlight at the lowest usable light setting. (Many modern LED flashlights allow you to adjust brightness output.)
Less Fragile than Conventional Gas-Powered Lanterns
LED flashlights are more sturdy and stable than kerosene or propane lanterns. They do not require users to gather any fuel beyond batteries.
Consistent Operation, Regardless of Temperature
Did you know an incandescent bulb can shatter if used in extremely cold temperatures? It’s true, and again it is due to the fact that incandescent bulbs run very hot. Any physics instructor would tell you that glass is one of many natural materials that expand with heat and contract with cold. We’re not talking about huge amounts of expansion – when filled with hot water, for instance, a glass will only expand about .02 percent. However, this is more than enough to cause cracks. The culprit is uneven heating. If some parts of the glass are warmer than others, the expansion process will not be consistent, and because glass has a low tolerance for being stretched, it will usually break. (Pyrex and other heat-resistant glass is engineered to have a very low level of thermal expansion.)
If you try to turn on an incandescent bulb in extremely cold temperatures, i.e. any temperatures below zero degrees Fahrenheit, the glass bulb will expand inconsistently and often shatter.
In contrast, LED flashlight bulbs remain usable in very cold temperatures because they do not emit heat. They run cold because their light production is dependent on positively or negatively charged ions finding their mates across semiconductor materials. This procedure does not radiate heat, as does a glowing filament in an incandescent bulb. With very little contrast between the bulb itself and the surrounding external temperature, LED flashlights can safely be used in extremely cold conditions. Indeed, with cold-resistant lithium batteries, LED flashlights can operate in temperatures as low as -50 degrees Fahrenheit.
Extremely Bright Light Output
When you’re stranded in the wilderness, your whole being yearns for a device that will somehow attract the attention of rescue workers. From flares to mirrors to messages spelled out in rocks or sticks, those in emergency situations quickly become creative about flagging down search parties. LED flashlights are superior to incandescent torches in emergency situations because they emit extremely bright light.
To appreciate the incredible brightness of an LED flashlight, consider that one lumen is equivalent to one birthday candle seen from a distance of one foot. The average incandescent bulb emits 17 lumens per watt of power. In contrast, an LED bulb can deliver more than 60 lumens with the same watt of power. Therefore, you get far more brightness with far less power when you choose an LED flashlight.
Superior Beam Distance
Beam distance is another variable that flashlight manufacturers measure. This is an important quality in emergency circumstances because a flashlight with a longer beam distance will send light farther into the darkness. When you’re stranded, a longer beam distance makes it more likely that emergency rescuers will notice your light. It’s also helpful to have a long beam distance even when you’re not hoping to attract searchers’ attention. When you’re alone in the woods, you want to know about a bear or other potential attacker as soon as possible; a long-beam flashlight gives you the advantage of seeing what’s coming as early as possible.
In general, LED flashlights have longer beam distances than incandescent flashlights. Part of this has to do with the fact that many LED flashlights can be adjusted to provide more a more focused, narrow beam of light. This feature allows you to choose focused light when beam distance counts, and more dispersed light for ambient lighting.