Subcutaneous layer or adipose tissues are the fat depositing layers found just below the skin or in between internal organs. They reduce the heat loss from the body and act as a good insulator. Animals of colder regions and fishes of cold water have thicker layer of subcutaneous fat, in order to retain heat in their body and thus maintaining the body temperature. Thicker the layer of subcutaneous fat, lesser will be the heat loss from the body.