Comparison of rectal and aural core body temperature thermometry in hyperthermic, exercising individuals: a meta-analysis.
OBJECTIVE
To compare mean differences in core body temperature (T(core)) as assessed via rectal thermometry (T(re)) and aural thermometry (T(au)) in hyperthermic exercising individuals.


METHODS
PubMed, Ovid MEDLINE, SPORTDiscus,  CINAHL, and Cochrane Library in English from the earliest entry points to August 2009 using the search terms aural, core body temperature, core temperature, exercise, rectal, temperature, thermistor, thermometer, thermometry, and tympanic. Study  Selection: Original research articles that met these criteria were included: (1) concurrent measurement of T(re) and T(au) in participants during exercise, (2) minimum mean temperature that reached 38°C by at least 1 technique during or after exercise, and (3)  report of means, standard deviations, and sample sizes.


METHODS
Nine articles were included, and 3 independent reviewers scored these articles using the Physiotherapy Evidence Database (PEDro) scale (mean = 5.1 ± 0.4). Data were divided into time periods pre-exercise,  during exercise (30 to 180 minutes), and postexercise, as well as T(re) ranges <37.99°C, 38.00°C to 38.99°C, and >39.00°C. Means and standard deviations for both measurement techniques were provided at all time intervals reported. Meta-analysis was performed  to determine pooled and weighted mean differences between T(re) and T(au).


RESULTS
The T(re) was conclusively higher than the T(au) pre-exercise (mean difference [MD] = 0.27°C, 95% confidence interval [CI] = 0.15°C, 0.39°C),  during exercise (MD = 0.96°C, 95% CI = 0.84°C, 1.08°C), and postexercise (MD = 0.71°C, 95% CI = 0.65°C, 0.78°C). As T(re) measures increased, the magnitude of difference between the techniques also increased with an MD of 0.59°C (95% CI = 0.53°C, 0.65°C)  when T(re) was <38°C; 0.79°C (95% CI = 0.72°C, 0.86°C) when T(re) was between 38.0°C and 38.99°C; and 1.72°C (95% CI = 1.54°, 1.91°C) when T(re) was >39.0°C.


CONCLUSIONS
The T(re) was consistently  greater than T(au) when T(core) was measured in hyperthermic individuals before, during, and postexercise. As T(core) increased, T(au) appeared to underestimate T(core) as determined by T(re). Clinicians should be aware of this critical  difference in temperature magnitude between these measurement techniques when assessing T(core) in hyperthermic individuals during or postexercise.
Korey Stringer Institute, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Storrs, CT 06269-1110, USA.
Robert
R
Huggins
Neal
N
Glaviano
Naoki
N
Negishi
Douglas J
DJ
Casa
Jay
J
Hertel
D056352:Athletes; D001831:Body Temperature; D001833:Body Temperature Regulation; D061827:Dimensional Measurement Accuracy; D004423:Ear; D015444:Exercise; D005334:Fever; D018883:Heat Stroke / Q000401:mortality; D006801:Humans; D012007:Rectum; D013177:Sports; D062125:Thermometry / Q000379:methods*