Infrared vision/doc

• This marks zombies and other warm-blooded monsters with a ? across the entire screen, including outside your "Full Night Vision" range. Shady zombies aren't so sneaky anymore!
• While Infrared Vision is effective, it should not be mistaken for 'X-Ray Vision'. Line-of-sight is still required, and certain objects will block your view (Such as glass!)
• See also The infrared vision mutation.