I have one of thoe little 2.5" LED flashlights, that have 9 small LEDs
and use 3 AAA batteries. It's like the ones that Harbor Freight
sometimes gives away free, same size, but nicer.

The guy I bought the first one from said it would run for days on one
set of batteries, but I forgot that it was still on and i put it in my
pocket and an hour or two later, I noticed it was on because it was
warm.

It's still really bright, but if it's noticeably warm, how long can the
baterries really last? Certainly not two days. ?


I once, recently, forgot the screen was lit on my 5.5" smart phone and
only noticed because it felt warm in my pocket.

It's got a proximity sensor but I don't remember what it's supposed to
do.