Temperature measurement

• several non-invasive methods, such as rectal, oral, ear and axillary temperatures are used to estimate the core temperature
  • the rectal temperature is higher than at other sites, traditionally oral and axillary readings are adjusted to the rectal temperature by adding 0.3°C and 0.5°C, respectively (1)
    • adjustments have a very limited scientific grounding (1)
    • also individual variability in temperature has been observed between right and left ear, and right and left axilla
    • in a study comparing the temperature results from oral, ear, axillary and rectal readings (1):
      • mean deviation between rectal temperature, and oral, ear and axillary temperatures, respectively, was > 0.5 degrees C, with a large individual variation
      • the authors concluded that, in order to improve the evaluation of body temperature, the assessment should be based on the individual variation, the same site of measurement and no adjustment of oral, ear or axillary temperatures to the rectal site

Reference:

1. Sund-Levander M et al. Errors in body temperature assessment related to individual variation, measuring technique and equipment. Int J Nurs Pract. 2004 Oct;10(5):216-23.