An image forming apparatus has a fixing unit that fixes a developer transferred onto a print medium. The apparatus includes a temperature detector and a movement detector. The temperature detector has a thermistor that detects a temperature of or near a fixing member. The movement detector detects that the thermistor has moved relative to the fixing member. The movement detector includes a first, second, and third electrically conductive members. The first electrically conductive member and a second electrically conductive member are connected to each other via the thermistor. The third electrically conductive member cooperates with the first electrically conductive member to form a first switch, and with the second electrically conductive member to form a second switch. When the thermistor moves out of contact engagement with the fixing member, at least one of the first switch and the second switch is closed.