The nurse is providing education to parents of a 7-year-old child who fractured an arm and is being discharged with a cast. Which instruction should be included in the teaching?

"Swelling of the fingers is to be expected for the next 72 hours."

"Call or return to the clinic if the fingers change color or get cool."

"Immobilize the shoulder to decrease pain in the arm."

"Allow the affected limb to hang down for one hour each day."