title: Is oral temperature an accurate measurement of deep body temperature? A systematic review.
abstract: BACKGROUND
  Oral temperature might not be a valid method to assess core body temperature. However, many clinicians, including athletic trainers, use it rather than criterion standard methods, such as rectal thermometry.
  
  
  OBJECTIVE
  To critically evaluate original research addressing the validity of using oral temperature as a measurement of core body temperature during periods of rest and changing core temperature.
  
  
  METHODS
  In July 2010, we searched the electronic databases PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTDiscus, Academic Search Premier, and the Cochrane Library for the following concepts: core body temperature, oral, and thermometers. Controlled vocabulary was used, when available, as well as key words and variations of those key words. The search was limited to articles focusing on temperature readings and studies involving human participants.
  
  
  RESULTS
  Original research was reviewed using the Physiotherapy Evidence Database (PEDro). Sixteen studies met the inclusion criteria and subsequently were evaluated by 2 independent reviewers. All 16 were included in the review because they met the minimal PEDro score of 4 points (of 10 possible points), with all but 2 scoring 5 points. A critical review of these studies indicated a disparity between oral and criterion standard temperature methods (eg, rectal and esophageal) specifically as the temperature increased. The difference was -0.50°C ± 0.31°C at rest and -0.58°C ± 0.75°C during a nonsteady state.
  
  
  CONCLUSIONS
  Evidence suggests that, regardless of whether the assessment is recorded at rest or during periods of changing core temperature, oral temperature is an unsuitable diagnostic tool for determining body temperature because many measures demonstrated differences greater than the predetermined validity threshold of 0.27°C (0.5°F). In addition, the differences were greatest at the highest rectal temperatures. Oral temperature cannot accurately reflect core body temperature, probably because it is influenced by factors such as ambient air temperature, probe placement, and ingestion of fluids. Any reliance on oral temperature in an emergency, such as exertional heat stroke, might grossly underestimate temperature and delay proper diagnosis and treatment.
authors.affiliation: Department of Kinesiology, Neag School of Education, University of Connecticut, 2095 Hillside Road, U-1110, Storrs, CT 06269-1110, USA. stephanie.mazerolle@uconn.edu
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Mazerolle
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Ganio
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Casa
authors.forename: Jakob
authors.initials: J
authors.lastname: Vingren
authors.forename: Jennifer
authors.initials: J
authors.lastname: Klau
mesh_terms: D001831:Body Temperature; D061827:Dimensional Measurement Accuracy; D005334:Fever; D018883:Heat Stroke; D006801:Humans; D009055:Mouth; D012007:Rectum; D062125:Thermometry / Q000379:methods*