the difference in temps in different body areas has always been the same.

a near normal rectal temp, especailly if taken after the morning will read 100.

the ear thermometer i have adjusts autotmaticly. it tells if the temp is in the normal range.

standard guide for adults and children:

Use a reliable thermometer to tell if you have fever when temperature is at or above one of these levels:

• 100.4° Fahrenheit (38° Celsius) measured rectally (in the bottom)
• 99.5° Fahrenheit (37.5° Celsius) measured orally (in the mouth)
• 99° Fahrenheit (37.2° Celsius) measured in an axillary position (under the arm)