A heater comprises a cap 20 formed by joining and fixing together curved peripheries 10a as peripheries of two semi-elliptical heat-generator-containing sheets 10 of generally the same shape. The heat-generator-containing sheet 10 comprises a waterproof inner layer sheet 2, an air-permeable sheet 5 disposed so as to cover the entire surface of the inner layer sheet 2, and a plurality of heat generators 3 interposed between and held by the inner layer sheet 2 and the air-permeable sheet 5, which generate heat when in contact with an air. The heat generators 3 are disposed substantially over the entire surface of the cap 20. The heat-generator-containing sheets 10 are joined and fixed together with the respective inner layer sheets 2 being the inner surface. The heater realizes a simple handling when in use, a small temperature variation, and simple fabrication process.
A hair warming tool is in the form of sheet and has at least one heating part in the center thereof and a margin around said heating part. It is designed to wrap tied hair in said heating part and to be held in place to keep the wrapping state by fastening the margin with a fastening means such as an elastic band, a string or a wire. A hair treating method comprises wrapping tied hair with a hair warming tool of sheet form having at least one heating part while leaving at least the part of the hair near the roots unwrapped to warm the hair.
