What happens when you die
Death is permanent for the character, not for the world. The save keeps running exactly as you left it: your base, your stockpiles, your vehicles and every door you barricaded stay where they are. Only the survivor is gone. The death screen then offers a new character or a way out to the menu.
What becomes of the body depends on infection. A character who dies clean leaves an ordinary corpse on the ground. A character who dies while carrying the Knox infection gets back up as a zombie, still wearing the same clothes and carrying the same inventory. The cause of death does not matter: an infected survivor who bleeds out still reanimates. On the default Apocalypse settings the Reanimate Time option is 0-1 Minutes, so the body rises almost at once. Both that timer and the 2-3 day Infection Mortality can be changed in the sandbox settings.
Build 42 has no save button and no reload. The game writes the character file the moment you die (one source), so the only way back is a copy of the save made beforehand.
