The most accurate way is by mouth or rectum. However many people use a thermometer that reads from the ear. Although this is convenient and less disruptive for a child, it is less accurate especially in children under 3 years of age.
Dr. Keely’s Tip:
It is important to be aware if your child has had two or more consecutive readings of 37.8°C or over. Be especially vigilant in the presence of an obvious cold or sore throat, or if your child has a history of kidney infections.