If you take a patient's oral temperature after he's consumed a hot or cold beverage, you'll get an inaccurate reading. Nurses researching this variable found that on average, a patient's temperature doesn't return to baseline for 15 minutes after he drinks a cold beverage. After he drinks a hot beverage, his temperature doesn't return to baseline for 23 minutes.
In a study conducted at the University of Virginia Health System, 43 nurses abstained from food, beverages, gum, smoking, and exercise for 1 hour before the researchers took their baseline temperatures with oral electronic thermometers. The study subjects then drank either a cold or hot beverage. Researchers recorded each subject's temperature every 3 minutes until temperature returned to baseline for two consecutive readings.
Based on their findings, researchers recommend waiting 15 to 25 minutes after a patient has consumed anything before taking his temperature. They presented their findings at the annual Academy of Medical Surgical Nurses Convention in Las Vegas, Nevada.