Dry mouth in fever is a reaction to higher body temperature that consumes a lot of water from the body, resulting in dehydration and dry mouth. Patients with fever, usually caused by infectious or bacterial colds, are more likely to have dry mouth. The infectious virus enters the body, invades the normal tissues of the body, and an increase in body temperature occurs, causing the patient to lose water and the circulation in the body does not go on smoothly, and the first reaction that occurs at this time is the symptoms of dry lips and dry mouth. Patients should be hydrated after the dry mouth reaction, preferably with warm water, which can also have a salutary effect on the cold. In addition, the patient can check the blood routine to clarify the cause and treat the symptoms.