Coma followed by fever is commonly seen in brain diseases, barbiturate poisoning, etc. 1. Brain diseases: such as cerebral hemorrhage, large cerebral infarction, brain stem infarction and so on. Because of the primary brain disease, there is a consciousness disorder which leads to coma, and then there is a central fever, or because of the long-term coma bedridden bed sores and aspiration pneumonia and other secondary infections, leading to subsequent fever. 2. Barbiturate poisoning: Barbiturates such as phenobarbital, sodium thiopental, etc., belong to the sedative-hypnotic agent, if overdose can lead to poisoning, inhibition of the central nervous system so that the patient is in a state of deep coma. Long-acting barbiturates poisoning, later can be complicated by aspiration pneumonia and other causes of fever. When comatose patients have fever, they should seek the help of doctors in time, improve the relevant examination, and clarify the cause of the disease, so as not to delay the condition.