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A brief report on the normal range of forehead temperature as determined by noncontact, handheld, infrared
Daniel Kwok-keung Ng1, Chung-hong Chan, Eric Yat-tung Chan
1Department of Paediatrics, Kwong Wah Hospital, Kowloon, Hong Kong. dkkng@ha.org.hk
Background:
Noncontact forehead temperature measurement by handheld infrared thermometer was used as a screening tool for fever. However, the accuracy data and normal range of forehead temperature determined by this method were not available.
Methods:
The temperature readings from 3 handheld infrared thermometers were validated against an electronic thermometer. Normal range of forehead temperature was determined by measuring the forehead temperature in 1000 apparently healthy subjects.
Results:
Significant differences were detected in readings obtained by the 3 different handheld infrared thermometers (analysis of covariance, P < .001) The most accurate one was chosen, and the normal range of forehead temperature in 1000 subjects detected by this method was 31.0 degrees C to 35.6 degrees C.
Conclusions:
Our study shows that commercially available, handheld infrared thermometers require individual validation. Forehead temperature in excess of 35.6 degrees C is suggestive of fever. Further studies are required to confirm accuracy of this value in detecting fever.
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