There are many reasons why the forehead of fever is not hot, commonly due to the external environment, temperature measurement error, thermoregulatory center disorders and so on. 1. External environment: Because the forehead area is exposed to the air for a long time, if the surrounding environment is cold, the forehead will dissipate heat faster, which will lead to a decrease in the local skin temperature, and the phenomenon of fever and forehead is not hot. 2. Temperature measurement error: this phenomenon occurs in low fever, due to the low fever state relative to the high fever state body surface temperature is slightly lower, if you only use the feel of the forehead to determine whether there is heat, or the quality of the thermometer used there are problems, there may be a fever due to the test error of the forehead does not heat the phenomenon. 3. Disorders of the thermoregulatory center: When the human body is in a feverish state, the nerve center regulating body temperature may be disturbed, and there will be fever and forehead not hot, this phenomenon is especially common in children. In order to avoid delay, patients should go to the regular hospital for diagnosis and treatment.