When you have a cold, you feel feverish, usually due to the following factors: First, the most common factors are bacteria, viruses, fungi and pathogenic microorganisms, such as mycoplasma and chlamydia, and other undesirable substances that invade the body, the body will produce an immune response, and therefore will produce antigenic and antibody complexes, which, in the formation of the immune complexes, will cause the body to have a fever. Secondly, when you have a cold, the hypothalamus nerve center will move up the thermoregulation point, which will also increase the body temperature, and at the same time, you will feel feverish. Third, in the process of antigenic microorganisms and immune factor release, the body will also release inflammatory mediators, such as prostacyclin, histamine, leukotriene and other substances, such inflammatory mediators in the body will also have the effect of self-heat dissipation, so the cold will feel feverish.