Call of Duty: World at War No Hud

Hide/Show Hud

1. Enable console from the in-game options. 
2. Press the Tilde "(~)" to open the console.
3. Type seta thereisacow 1337 and press Enter.
4. In-game type this to toggle hud on/off:

cg_draw2D 0
cg_draw2D 1

Useful commands

To enable Cheat Mode you need to type map name to the console. For example, devmap ber1. Here is the full list:

Devmap ber1 - Ring Of Steel
Devmap ber2 - Eviction
Devmap ber3a - Heart of the Reich
Devmap ber3b - Downfall
Devmap mak - Semper Fi
Devmap nazi_zombie_prototype - Nacht der Untoten
Devmap pby_fly - Black Cats
Devmap pel1 - Little Resistance
Devmap pel2 - Hard Landing
Devmap oki2 - Blowtorch & Corkscrew
Devmap oki3 - Breaking Point
Devmap pel1a - Burn 'Em Out
Devmap pel1b - Relentless
Devmap see1 - Their Land, Their Blood
Devmap see2 - Blood and Iron
Devmap sniper - Vendetta

Here are some useful commands:

cg_drawgun 0/1   //removes weapon
cg_fov <>   //changes the FoV (values must range between 60 and 160)
noclip   //enables ‘no clipping’ so you can walk through walls
notarget   //this will disable the AI so that the enemy soldiers will ignore you

Source

• Call of Duty Developer console ; on Call of Duty wikia
• Cheat Codes ; call-of-duty.alteredgamer.com

Screenshot

Call of Duty World at War No Hud