I always have one of these in my carry-on. I use it if I am out walking at night. I use it if I need to get up in the middle of the night for a bathroom break or the like and I don't want to disturb anyone else that is sleeping. I also like to know I have it in case of a power outage, emergency, or fire etc.

Your phone may have that built in but do you really want to be draining your phone battery with the light if you are in a real emergency? Not to mention, how visible would the phone light be as a signal to any overhead aircraft that might be searching?

Get yourself a small LED flashlight like this one and save yourself the worry. I have 4 of these little (‎1.38 x 1.38 x 4.68 inches) LUXPRO hand held ones stashed at strategic points in the house. LUXPRO even makes some fun glow in the dark gel colored models too if you prefer. Another reason I bring the flashlight is to check the hotel room thoroughly for any signs of bed bugs.

Also available in a rechargeable USB-C format.