What are sleepers and what happens to my character when I log out?
When you log out of the game, your character does not disappear - it stays in the world as a "sleeper."
Your sleeper remains at the exact location where you logged out, lying on the ground with all your inventory and equipment still on them.
Other players can find your sleeper, kill it, and take everything.
Your sleeper also continues to consume food and water while you are offline - if either reaches zero, the character dies and drops all loot.
To protect yourself, always log out inside your base behind locked doors.
Also, never log out while standing in water - your character will drown and die. To protect yourself, always log out inside your base behind locked doors and on dry ground.
The backpack goes into the sleeper too - anyone looting the body sees its contents behind a second tab.
Short video with an explanation: