We describe three cases of insomnia due to a feeling of heat in parts of the body, successfully treated with saikokeishito. Case 1 was a 50-year-old man who felt hot in his trunk and extremities at night. Case 2 was a 57-year-old women with osteoarthritis in the fingers who felt hot in her back at night. Their heat/pain was regarded as shisetsuhanto, or vexing pain in the extremities as described in “Shang Han Lun.” Case 3 was another 57-year-old woman who reported hot flushes both day and night. She did not have vexing pain in her extremities, but developed a rash. Although three patients felt hot, they all felt chill when they took off a blanket. Their heat vexation and intolerance of cold were considered as zokansonetsu, as seen in saikokeishito syndrome. They had kyokyokuman, or objective tenderness in the hypochondrium. However, they differed in shinkashiketsu, or tightness below the heart, another characteristic physical findings of saikokeishito : case 1 had stuffiness and rigidity below the heart and abdominal muscle contracture, case 2 had hardness and stiffness in zhong wan (middle segment of the stomach), and case 3 had mild stuffiness and rigidity below the heart, in terms of signs classically reported by Japanese doctors in the Edo period. These findings may suggest that saikokeishito has a wide range of indications. The three cases shared several characteristics, such as during menopause, without cold limbs, moderate or hypofunctional body energy, and alternating heat and chills. Saikokeishito could be a good medicine to treat patients suffering from insomnia with such symptoms, especially during menopause.