A temperature protection device basically includes a temperature detector, a temperature estimator, an overheated determining component and an overheating protection component. The temperature detector detects a temperature of a semiconductor component. The temperature estimator estimates an estimated temperature of the semiconductor component. The overheated determining component determines whether the semiconductor component is in an overheated state based on the detected temperature and the estimated temperature by using a first estimated temperature as the estimated temperature at a time point when the detected temperature has reached a first threshold temperature and a second estimated temperature that is estimated subsequent to the time point as the estimated temperature when the detected temperature has reached the first threshold temperature. The overheating protection component protects the semiconductor component from the overheating based on a determination made by the overheated determining component.