Comparisons of rectal, femoral, axillary, and skin-to-mattress temperatures in stable neonates.

The purpose of this study was to compare four sites for temperature recording in the neonate: rectum, femoral, axilla, and skin-to-mattress. Simultaneous measurements were made at the four sites in 99 stable, term neonates. Temperatures were recorded each minute for 15 minutes. The optimal temperatures (highest temperature recorded minus 0.2 degrees F) did not vary across the four sites, but there were significant differences in the mean times required to achieve optimal temperature and in the optimal placement times (time required for 90% of the subjects to reach optimal temperature). The rectal site required significantly less time than the other sites (M = 2.66 minutes, optimal placement time = 5 minutes). The femoral and axillary sites required significantly more time than rectal and significantly less time than skin-to-mattress (M = 6 minutes, optimal placement time = 11 minutes). The skin-to-mattress site required significantly more time than the other sites (M = 8.5 minutes, optimal placement time = 13 minutes).