Prediction of oesophageal temperatures from core temperatures measured at other sites in man

Transient changes in core temperature were induced in seven subjects by immersion in a hot, then a cold, bath and by light intermittent exercise. Measurements of core temperature were made at four sites: the external auditory canal, the oesophagus, the rectum and the gastrointestinal tract. A mathematical model was derived to enable prediction of oesophageal temperature from measurements made at any one of the other sites. The equations for auditory canal and rectal temperatures were very similar to those previously derived in the Institute of Aviation Medicine; use of an equation to predict oesophageal temperatures from gastrointestinal tract temperatures measured in the field using a radio-pill would therefore appear to be reasonable.