This paper discusses the preschool classroom needs of the imperceptibly handicapped child who has a medically-diagnosed physical condition which includes unpredictable episodes placing the child in a temporary state of dysfunction. (epilepsy, juvenile diabetes, and severe allergies are examples of such handicaps.) In most cases the child is capable of functioning normally in the classroom. It is suggested, however, that the development of knowledge, awareness, and understanding on the part of teachers and peers will encourage the development of a positive self-concept and will increase the child's changes for success in the preshcool program. The importance of developing close communication among family, physician, and the preschool teacher is emphasized. It is suggested that the preschool teacher can provide a valuable service by developing a local program bringing together these three groups to share information and increase their understanding of the characteristics and management of these physical conditions. A description of the symptoms of epilepsy and juvenile diabetes is provided and the teacher's role in coping with periodic seizures or insulin reactions is discussed. (BD)