A human body is cooled at an appropriate temperature, and a sufficient usage time is ensured. A cooling tool according to one aspect of the present invention is a cooling tool for cooling a human body, including a freezing material 30a that undergoes a phase change at a particular temperature and a first container containing the freezing material 30a. The first container transfers heat between the human body and the freezing material at a contact surface in contact with the skin of the human body. At least the contact surface has a thermal effusivity within the possible range of thermal effusivity of the skin of the human body. The contact surface may have a thermal effusivity (J/(m2˜S1/2·K)) of 1,000 to 2,000.