The relationship between axillary and core body temperature measurements.

The goal of this study was to assess the accuracy of the axillary site as an indicator of core body temperature. Data from 30 core body temperatures, 30 electronic axillary temperatures, and 30 mercury-in-glass axillary temperatures in nonpostoperative intensive care unit patients are reported. Core and axillary temperatures were simultaneously measured in each patient. The correlation between core and axillary-mercury was r = 0.90. The mean difference between core and axillary-mercury was 0.35 degrees F (0.19 degrees C). The correlation between core and axillary-electronic was r = .87. The mean difference between core and axillary-electronic was 0.6 degrees F (0.33 degrees C). Only three, or 5%, of the 60 core-axillary pairs met the expected 2 degrees F (1.2 degrees C) difference. These findings support the accuracy of axillary temperature measurement as a reflection of core body temperature measurement in nonpostoperative patients. These researchers suggest that mercury thermometers be used in cases where small differences in temperature are clinically meaningful.