Our cheeks may blush when we are angry, anxious or embarrassed. Blushing is the involuntarily reddening of the face, usually triggered by emotions. In sudden emotional changes, the body secretes adrenal hormone and there is an increase in body temperature. This alerts the autonomic nervous system which enlarges the blood vessels of the face, increasing the hot blood flow to the face. This makes the skin on the face appear red, hence, the reason for getting red cheeks when we blush.