Re-examination of tympanic membrane temperature as a core
temperature.
Sato, Kent T., Neal L. Kane, Gyula Soos, Carl V. Gisolfi, Narihiko
Kondo, and Kenzo Sato.
Marshall Dermatology Research Laboratories, Departments of
Dermatology and Exercise Physiology, University of Iowa College of
Medicine, 271 Medical Laboratories, Iowa City, Iowa 52242, Phone:
(319) 335-8085, FAX: (319) 335-8108
APStracts 2:0512A, 1995.
Controversies surrounding tympanic temperature (Tty) itself and
techniques for measuring it have dampened the potential usefulness of
Tty in determining core temperature (operationally defined here as
the body temperature taken at a deep body site). The present study
was designed to address the following questions: 1. Can a tympanic
membrane probe be made that is safer and more reliable than its
predecessors?, 2. Why is the effect of facial cooling and heating on
Tty so inconsistent in reports from different laboratories?, and 3.
Is Tty still useful as a measure of core temperature? Data from this
study, obtained with a modified thermocouple probe, suggest that the
widely reported facial skin cooling effect on Tty is most likely due
to thermal contamination from the surrounding ear canal wall and/or
suboptimal contact of the probe sensor with the tympanic membrane
because; 1 Tty that fell during facial cooling was increased to the
precooling level by repositioning the probe sensor, 2. Tty determined
using a probe with a larger sensor area (the sensor soldered to a
steel wire ring) tended to fall in response to facial cooling whereas
Tty determined with a thermally insulated probe ring did not, and 3.
Tty obtained under careful positioning of the insulated probe was
relatively insensitive to facial cooling or heating. Since Tty was
practically identical to esophageal temperature (Tes) in the steady
state, i.e., (in oC) 36.83 +/- 0.20 (SD) for Tty and 36.87 +/- 0.16
for Tes, n=11, at room temperature, and since facial cooling had
little effect on both Tty and Tes (36.86 +/- 0.17 for Tty and 36.86
+/- 0.26 for Tes during facial or scalp skin cooling), we support the
postulate that Tty is a good measure of core temperature. The
temperature transient in response to foot-warming was detected 5 min
(n=2) faster with Tty than with Tes. Thus with further improvements
in the design of the probe, Tty can become a standard for
determination of core body temperature.
Received 12 October 1994; accepted in final form 7 November 1995.
APS Manuscript Number A1055-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95