In act two, scene one, Macbeth begins to hallucinate and sees the image of a bloody dagger leading him to King Duncan's chamber. Macbeth immediately questions the "fatal vision" and wonders if it is simply a figment of his imagination. He questions whether the image of a bloody dagger is a "false creation," which is "Proceeding from the heat-oppressèd brain." Macbeth is wondering if he is physically suffering from a fever (this is the meaning of the phrase "heat-oppressed brain"). Macbeth is concerned that his intense emotions may have caused his blood to become overheated, leading to altered perception. Macbeth is experiencing a myriad of emotions, including doubt, anxiety, stress, and pressure. He is essentially wondering if his heated emotions have affected his brain, causing him to hallucinate and see an imaginary bloody dagger. At the end of the soliloquy, Macbeth acknowledges that his emotions, thoughts, and tortured soul (rather than some external element) are responsible for the "fatal vision," and he proceeds to enter the king's chamber to commit regicide.