This paper describes a method for change detection of sleeping conditions based on distributed sensing of the comforter using the multiple Internet of things (IoT) devices. The method detects the changes of the ambient conditions of the sleeping environment in the bed such as the falling off and turning over the comforter that is on the bed based on the continuous sensing of the temperature, humidity, and static acceleration of each part of the comforter. These sensing data change more gradually compared with the motion of the comforter. This method detects when the comforter falls off the bed and the comforter is turned over, which are important to prevent the patient from feeling unwell due to the decrease in body temperature when the comforter shifts from the body of the sleeping person. The experimental results show the feasibility of the proposed method.