Avoiding detection: can you fool an infrared security camera?

In The Thomas Crown affair, Pierce Brosnan is Thomas Crown, a rich playboy who spends his time stealing priceless pieces of art. In one scene Crown steals a precious painting from an art gallery. The painting is in a room with thermal imaging (infrared) security cameras. These cameras image heat rather than light so they work well during the day or at night. Before Crown steals the painting he leaves a suitcase in the room containing a heater, switched on. He does this to raise the temperature of the room and swamp the sensitivity of the camera - producing a 'white-out' on the screens - which allows him to go about his business unseen. So can you fool a state-of-the-art thermal camera by using this trick?