• True core temperature is generally considered to be 1) Pulmonary Artery or 2) Esophageal or 3) Bladder temperature but these are obviously invasive. A calibrated mercury-in-glass thermometer used orally or rectally may be employed if properly left in place for about 3 minutes as a “referee device” for resolving temperature comparisons.
  • Alternatively, a properly placed electronic predictive thermometer used orally or rectally and set to the “monitor” mode may be employed. It’s important to ensure that all comparisons are made in the proper “equivalence” mode on the thermometer being tested e.g. oral, rectal, axillary, etc. Temperatures taken at different sites will most often not be identical, but in sufficient agreement for routine clinical purposes.