Warmth in the hands and feet during sleep can be caused by a variety of reasons. After excluding fever caused by various infections, the most common ones are autonomic dysfunction, hyperthyroidism and so on. 1. Autonomic dysfunction: In addition to the symptoms of fever in the hands and feet while sleeping, there are also symptoms such as dreaming and insomnia. 2. Hyperthyroidism: Early symptoms depend on the severity of the disease and the organs involved, some patients may experience nervousness and anxiety as well as lack of concentration, while some may experience fear of heat and nervousness and anxiety. As the disease continues to progress, symptoms such as proptosis and periodic paralysis or muscle weakness are presented. There are many other causes of fever in the hands and feet while sleeping, and it is recommended to consult a doctor in time to determine the treatment plan under the guidance of a physician, and avoid blindly using medication on your own.