How do I get a more accurate reading from my Avent digital thermometer?

Suggestions to increase accuracy are:
Use the digital thermometer rectally for a more accurate reading. Oral (mouth) or axial (armpit) can be used but won't be as accurate. It would be beneficial for the thermometer to be at room temperature before use and a reading taken, which will take 10 seconds. If the “Lo” or “Hi” is displayed, the reading is outside the temperature range. The thermometer should be switched off, repositioned and then turned on again to take a reading.