Division of Emergency Medicine, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA. david.greenes@childrens.harvard.edu
By using temporal artery and rectal thermometers, we followed temperatures in 45 febrile (>38.5 degrees C) infants given an antipyretic drug. Sixty and 90 minutes after drug administration, temporal artery temperatures had decreased significantly more than rectal temperatures. When body arterial temperature changes rapidly, changes in rectal temperature may lag.