A nurse is assessing a just-born, full-term newborn under th…

A nurse is assessing a just-born, full-term newborn under the radiant warmer in the nursery and makes the following observations: 4006 grams (8 lbs. 8 oz.), 21 inches long, TPR: 97.5° F (36.4° C), 158, 56, jittery, pink body with bluish hands and feet, crying. Which of the following nursing actions is of the highest priority?