Assessing the Validity of Aural Thermometry for Measuring Internal Temperature in Patients With Exertional Heat Stroke

ContextThe use of aural thermometry as a method for accurately measuring internal temperature has been questioned. No researchers have examined whether aural thermometry can accurately measure internal body temperature in patients with exertional heat stroke (EHS).ObjectiveTo examine the effectiveness of aural thermometry as an alternative to the criterion standard of rectal thermometry in patients with and those without EHS.DesignCross-sectional study.SettingAn 11.3-km road race.Patients or Other ParticipantsA total of 49 patients with EHS (15 men age = 38 ± 17 years], 11 women age = 28 ± 10 years]) and 23 individuals without EHS (10 men age = 62 ± 17 years], 13 women age = 45 ± 14 years]) who were triaged to the finish-line medical tent for suspected EHS.Main Outcome Measure(s)Rectal and aural temperatures were obtained on arrival at the medical tent for patients with and those without EHS and at 8.3 ± 5.2 minutes into EHS treatment (cold-water immersion) for patients with EHS.ResultsThe mean difference between temperatures measured using rectal and aural thermometers in patients with EHS at medical tent admission was 2.4°C ± 0.96°C (4.3°F ± 1.7°F; mean rectal temperature = 41.1°C ± 0.8°C 106.1°F ± 1.4°F]; mean aural temperature = 38.8°C ± 1.1°C 101.8°F ± 2.0°F]). Rectal and aural temperatures during cold-water immersion in patients with EHS were 40.4°C ± 1.0°C (104.6°F ± 1.8°F) and 38.0°C ± 1.2°C (100.3°F ± 2.2°F), respectively. Rectal and aural temperatures for patients without EHS at medical tent admission were 38.8°C ± 0.87°C (101.9°F ± 1.6°F) and 37.2°C ± 1.0°C (99.1°F ± 1.8°F), respectively.ConclusionsAural thermometry is not an accurate method of diagnosing EHS and should not be used as an alternative to rectal thermometry. Using aural thermometry to diagnosis EHS can result in catastrophic outcomes, such as long-term sequelae or fatality.