The effect of hot beverages, cold beverages, and chewing gum on oral temperature

BACKGROUND: A prospective blood donor's oral temperature is affected by ext ernal stimuli such as drinking a hot or cold beverage or chewing gum. These stimuli can cause a deferral or an inappropriate acceptance for a certain unknown time. STUDY DESIGN AND METHODS: Ten volunteer subjects were exposed to each of th e three stimuli in separate studies. Oral and tympanic membrane temperature s were taken before exposure, immediately after exposure, and at various ti mes until the subject's temperature returned to baseline. RESULTS: The drinking of a hot beverage caused an immediate mean temperatur e elevation of 2.6 degreesF which would lead to deferral for 7 of 10 subjec ts. All subjects were acceptable for blood donation (temperature < 99.6 deg reesF) by 5 minutes. A cold beverage lowered the temperature; the temperatu re in 6 subjects returned to baseline by 10 minutes and that in 4 did so by 30 minutes. Gum chewing caused minimal temperature elevations; only 1 dono r's temperature reached 99.6 degreesF, and it was at acceptable levels for blood donation by 5 minutes. CONCLUSION: Drinking a hot beverage and, to a much lesser degree, gum chewi ng can lead to a deferral for elevated temperature, but subjects were accep table by 5 minutes. Cold beverages are of more concern, because they suppre ss the temperature for a short time and could theoretically lead to accepta nce of a febrile, possibly infectious donor.