There’s an interesting thing with the thermal scope in Call of Duty: Modern Warfare.
Infinity Ward has decided to take a more realistic approach to the entire aspects of the game, and Infinity Ward MP Designer has stated that there’s a change to the thermal scope in Call of Duty: Modern Warfare.
Thermal Scope in Modern Warfare cannot see through smoke, a big change compared to previous Call of Duty games. Infinity Ward says that this is to be more “realistic” for the entire game.
Infinity Ward said “this is not a bug.”