Emergency Room

Emergency Room is an achievement for Halo: Reach multiplayer matchmaking added with the Anniversary map pack. It is obtained by infecting 3 players in a single round in a matchmade Infection game.^[1]

Sources[]

↑ halo.xbox.com - The Halo Bulletin 10/19/11

Achievements in Halo: Reach

Campaign

The Soldier We Needed You To Be • Folks Need Heroes... • Gods Must Be Strong • A Monument to All Your Sins • We're Just Getting Started • Protocol Dictates Action • I Need a Weapon • To War • You Flew Pretty Good • Into the Howling Dark • Dust and Echoes • This Is Not Your Grave • Send Me Out... with a Bang • They've Always Been Faster • Two Corpses in One Grave • Your Heresy Will Stay Your Feet • Banshees, Fast and Low • If They Came to Hear Me Beg • ‎Wake Up, Buttercup • Tank Beats Everything • Lucky Me • ‎KEEP IT CLEAN • I Didn't Train to Be a Pilot

Firefight

Crowd Control • Knife to a Gun Fight • Score Attack • Firestarter • Blaze of Glory • Heat in the Pipe • Game, Set, Match

Multiplayer

Be My Wingman, Anytime • Skunked • What's a Killing Spree? • Yes, Sensei

Training

Doctor, Doctor • That's A Knife • I See You Favor A .45 • An Elegant Weapon... • Swap Meet • A Spoonful of Blamite

Player Experience

Make It Rain • A New Challenger • The Start of Something • An Honor Serving • A Storage Solution • Make it Drizzle • Cool File, Bro • Lemme Upgrade Ya • One Down, 51 to Go

Map Packs

Noble	Totally Worth It • Both Barrels • Cross-Mappin' • You Ate All the Chips • You Blew It Up! • Poppin' & Lockin' • Offensive Driver

Defiant	Return to Sender • Candy From a Baby • Crackin' Skulls • Don't Touch That! • Paper Beats Rock • All Alone

Anniversary	Top Shot • Emergency Room • Stick it to the Man • Dive Bomber • License to Kill • Bounty Hunter • From Hell's Heart

Fan Feed