Comparison of ear to rectal temperature measurements in infants and toddlers

The purpose of this study was to compare arterial heat balance ear temperat ure measurements to rectal temperatures in infants and children and to dete rmine the ability of the ear thermometer being tested to detect fever. From 12/95 to 2/96, 1,175 pairs of ear and rectal temperature measurements were prospectively obtained from 140 infants and toddlers. The mean rectal temp erature was 37.58 degrees C (sd=0.68) and the mean ear temperature was 37.6 0 degrees C (sd=0.85). However, at the low end of the rectal temperature sc ale, ear temperatures tended to be higher, and at the high end of the recta l temperature scale, ear temperatures tended to be lower. There were 292 re adings with a rectal temperature greater than or equal to 38.0 degrees C an d in 204 (70%) the ear temperature was also greater than or equal to 38.0 d egrees C. A retrospective analysis of 53 children who became febrile in hos pital (ear or rectal temperature greater than or equal to 38.0 degrees C) s howed that fever was detected first by rectal measurement in seven, by ear measurement in 31 (59%), and by both in 15 (28%), These data indicate that, on the average, rectal and ear temperature measurements are not different. Fever that developed in children after hospitalization was more likely to be first detected by ear than by rectal measurement.