As posted before, I never felt embarrassed when as a child, my mother took my rectal temperature, nor when as an adult I had my temperature taken by the women I lived with.
The only embarassing experience of rectal temperature taking I have had in my whole life was when, back in 1970 , just as I turned 18, as part of my last high school physical, the attractive female schooldoctor took my rectal temperature standing up.
Two other women were present in the room, the school nurse and the school psycologist. And they did not miss anything of the show.
I felt deeply humiliated as the lady, after the genital exam, asked me to turn around and then, without notice, parted my buttcheeks and inserted a thermometer deep in my rectum. She then kept her hands on my buttocks as the thermometer registered.
I find it hard to say which moment of the whole procedure was the most embarassing or humiliating, probably when the thermometer was inserted or tbe long waiting time when I was standing with the thermometer planted in my ass like a baby.