Abstract: A message spreading apparatus is disclosed to generate an audio message output in response to the presence of a heat radiation generated by body heat. A housing has a front wall provided with an opening therein and a rear wall including a first portion opposed to the opening of the front wall, with the front wall and the rear wall being spaced a predetermined distance from each other. A radiation reflecting member is mounted to the first portion of the rear wall and is configured and arranged so as to reflect a portion of a heat radiation ray entered through the opening of the front wall to a path which is between the front wall and the rear wall and is in a direction substantially parallel to the respective planes of the front and rear walls. A pyroelectric sensor is provided in the path to sense the reflected heat radiation ray and generate an activating signal in response to the reflected heat radiation ray.