Rectal temperature measurement is considered the most precise method for assessing core body temperature and typically registers higher than oral temperature. For adults, the rectal thermometer should be inserted 1 to 1.5 inches into the rectum to obtain the most accurate reading.

Follow these steps for rectal temperature assessment:

Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.

Step 2: Position the patient in a side-lying position to better visualize the rectal area.

Step 3: Expose only the anal region, maintaining patient warmth and privacy.

Step 4: If present, clean the anal area of any feces or secretions. Remove soiled gloves, perform hand hygiene, and put on clean gloves.

Step 5: Retrieve the thermometer from its charging unit and attach the rectal thermometer probe stem.

Step 6: Securely fit a disposable plastic probe cover over the thermometer probe stem to prevent infection transmission.

Step 7: Apply a generous amount of water-soluble lubricant to the thermometer, covering the first 1 to 1.5 inches. Lubrication minimizes rectal discomfort.

Step 8: Using the non-dominant hand, gently part the patient's buttocks to expose the anus. Advise the patient to take slow, deep breaths and relax, which helps ease the insertion of the thermometer by relaxing the anal sphincter.

Step 9: Carefully insert the lubricated thermometer toward the umbilicus up to about 1.5 inches. Ensure the probe is inserted correctly to optimize contact with rectal blood vessels.

Step 10: If resistance is felt, cease insertion to avoid damaging the rectal mucosa.

Step 11: Hold the thermometer steady until the thermometer beeps, signaling that the reading is finished. Record the temperature displayed on the thermometer unit.

Step 12: Press the ejection button to release the probe cover. Safely dispose of the probe cover and clean the thermometer stem with an alcohol swab, particularly around any ridges or connections.

Step 13: Clean the patient's anal area with soft tissue to remove any lubricant or fecal residue. Discard the tissue and perform any additional perineal hygiene as needed.

Step 14: To conclude the procedure, remove and dispose of gloves in a designated container and perform hand hygiene.

Step 15: Document the temperature and all procedural steps accordingly.