The first step in the development of fever in the arm is to determine whether there is a suppurative infection. Localized open trauma, surgical aseptic operation is not strict, peripheral septic infection through the blood transmission can lead to septic infection of the arm, appear local redness, swelling and hot pain. Prolonged physical exercise or overwork can lead to increased blood circulation in the arm, which can also lead to localized heat. Nerve damage (cervical spondylosis and peripheral nerve damage) can cause localized sensory abnormalities in the arm, which can also lead to localized warmth.