How do you expose the tympanic membrane before taking an aural temperature in children younger then 3 years?

To expose the tympanic membrane in children younger than 3 years, gently pull the ear back and down. This maneuver straightens the ear canal, allowing for better access to the tympanic membrane. Once the ear is positioned correctly, you can insert the thermometer into the ear canal to take the aural temperature accurately. Always ensure the child is calm and comfortable during the process.