In an Infection match, the Last Man Standing is the last uninfected player in the game. The Zombies in the match will see a waypoint above the Last Man Standing's head, making it extremely difficult for the uninfected to hide. This status was introduced in Halo 3.
By definition, there can only be one Last Man Standing in a given match. The Last Man Standing will receive a medal for attaining the status, and an icon will be displayed at the bottom of the screen, reminding the player of their perilous and likely short-lived status as the last human alive. Custom Game settings allow special characteristics to be set for the Last Man Standing. In Halo: Reach, the Last Man Standing is given a small Overshield.
Usually, human players will resort to camping in an easily defendable area, sometimes on a corner or by a lift. A popular place is on the Bungie Forge World map, The Cage, on the corner up the slant by the man cannon. Zealot's anti-gravity level is also a good defense spot. Another great spot is behind the teleporter on Sanctuary.