Before being very dismissive, please consider the alternative that I do know about the things you mention, and that there are other ways of looking at the situation.

1. If the ear temperature are consistently wrong (systematic error) it is very easy to debias them and they become equivalent (modulo random error) to anal temperatures.

2. Perhaps cephalic temperature is a better diagnostic tool than gut temperature to evaluate the effects of fever? After all, the brain is a more sensitive organ than the butt.

> the brain is a more sensitive organ than the butt

The more time I spend on the internet, the less certain of this I become.