The  nurse is caring for a client who is receiving a unit of…

The  nurse is caring for a client who is receiving a unit of packed RBCs. About 15 min following the start of the transfusion, the nurse notes that the client is flushed and febrile, and reports chills. To help confirm that the client is having an acute hemolytic transfusion reaction, the nurse should observe for which of the following manifestations?