You can enable it anywhere

One of my favorite Fallout experiences ever (and I'm including the wonderful Interplay era) is playing New Vegas on a modded survival mode. A minimal HUD, and requirements like finding water on a constant basis made the game pretty damn thrilling, not to mention the fact that you could actually play a role, unlike the one forced onto you in Fallout 4, and to a lesser extent, Fallout 3.

Clever folks over at reddit have recently mined the game and found new details for Bethesda's upcoming survival mode update for Fallout 4, which the publisher has now confirmed. Essentially, you can enable it anywhere with a simple menu swipe, and it instantly allows you to do more (as well as take more) damage. Manual and quicksave options are disabled, and you'll need to sleep at least an hour to save. Fast Travel is completely gone.

Beyond that, enemies won't show up on your compass, and fatigue actually...matters now. You can read a whole bunch of other minute details here in the full log. It all sounds fun, but it just makes me want to play New Vegas again.

Fallout 4 Survival Mode Full Overview (extracted from in-game files) [reddit]