There are many capillaries in the ears, and when people encounter happy or angry things, it causes emotional excitement and excitement in the cerebral cortex and plant nerves, so the capillaries in the face and ears expand and fill with blood, making the ears red. The capillaries in the face and ears expand and become engorged with blood, making the ears red and hot. 2. Ear fever is closely related to the microcirculation of the human body. Changes in temperature and nerve stimulation can affect the blood vessels in the skin of the ears, and blood rushes to the ears to make them hot, especially when cold and heat stimulation can also accelerate the contraction or diastole of capillaries in the microcirculation. 3. The blood vessels in the skin of the ear are normally contracted and not much blood flows through them, so they do not feel hot. When we rub our ears with our hands, these blood vessels are stimulated to expand, and the amount of blood flowing through them increases greatly because the blood is hot, so then we feel our ears get hot. 4. When exercising, blood flow throughout the body is accelerated, and after stopping exercising, more blood flow will go through the head and face, so the ears may also become red and hot because of the accelerated blood flow. Ear fever is a normal physiological phenomenon, so there is no need to worry or stress too much about it.