There are many clinical causes of unconsciousness due to high fever. First of all, cerebrovascular diseases such as cerebral hemorrhage due to hypertension, massive cerebral infarction, subarachnoid hemorrhage, etc. can easily lead to coma. Secondly, patients with respiratory failure can become unconscious, and severe pneumonia or chronic obstructive pulmonary disease can also lead to high fever and unconsciousness due to the development of pulmonary encephalopathy. Then, severe liver disease can cause hepatic encephalopathy, which can lead to coma with high fever. Diabetic ketoacidosis, hyperosmolar coma, and pyrexia can also cause these symptoms. Therefore, if you are unconscious with high fever, you must be sent to the hospital in time to further improve the examination in order to clarify the cause of the disease and to treat the cause in a timely manner.