I'm once again at Falls Creek Church Camp cooking for hungry teenagers till my body is ready to collapse into bed at night. We had a cooking staff change and I drew the top bunk this year. I haven't slept in a bunk bed since college and Not surprisingly, everyone's first thought is "will I fall off?" There's other things to consider though.
First gear up mentally and physically to hoist your body up that ladder. 1 X 4 boards don't look so thin. Remember when you were in third grade and you scampered up and down the ladder from a bunk bed? Yeah, well, likely your body weight has changed since then and the pain can be torturous to aged feet.
Then look at the spot on the bed that you will flop onto once you reach the top. If sadly this space has been filled with things like your iPad, magazines and camp mail, there are two choices. Hang on by your elbows and attempt to clear a landing point or resign yourself to climbing back down to move stuff, knowing that you must go through the foot pain process again.
Have supplies handy. Getting a tissue or lip balm or taking that nightly bathroom break is not so easy. Be willing to wake your lower bunk mate up if everyone has been so kind as to go to sleep with the light on. Unless of course you want to climb the ladder again.
So really, falling out of bed while sleeping isn't that great of a concern. Falling out of bed while trying to get down is.