For phototherapy at the hospital, a light box and/or fiber-optic blanket directs fluorescent light onto the jaundiced baby. The baby lies in an enclosed crib (incubator) while light is absorbed into the skin. The light changes bilirubin into a form that the baby can more easily get rid of in his or her stool and urine.

The baby is undressed so that as much of the skin as possible is exposed to the light. And the eyes are covered to protect them from the bright light.

For phototherapy at home, a fiber-optic blanket or band may be used by itself.