A preliminary study on influence of negative air ions generated from pajamas on core body temperature and salivary IgA during night sleep - Wakamura, Tomoko; Sato, Maki; Sato, Akihiro; Dohi, Takahiro; Ozaki, Kazuto; Asou, Norio; Hagata, Shigeru; Tokura, Hiromi (Nofer Institute of Occupational Medicine)