A red face can appear after exercise - or anytime you're hot, angry, embarrassed, or stressed. This type of facial redness comes from dilation of blood vessels in the face due to the action of stress hormones such as epinephrine and norephinephrine - released in response to stress, exercise, or heat. Having a fever can also cause a red face, as the body tries to eliminate heat by opening up the blood vessels near the skin's surface.