In daily life, many people experience ear fever. Ear fever is inextricably linked to capillaries and microcirculation, and can be caused by the following conditions: 1. There are many capillaries in the ears. The change in temperature and nerve stimulation can affect the blood vessels in the skin of the ears, and blood rushes to the ears to heat them up, 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 ears are usually contracted, and not much blood flows through them, so they don’t feel hot. When we rub our ears with our hands, these blood vessels are stimulated to expand and the amount of blood flowing in them increases greatly because the blood is hot, so then we feel our ears getting hot; 4. When exercising, the blood circulation is accelerated throughout the body and after stopping the exercise, more blood flows through the head and face, so the ears may also become red and hot because the blood flow is accelerated. Ear fever is a normal physiological phenomenon and there is no need to worry and stress too much about it.