She held the thermometer so I could see it. It was a glass mercury B-D thermometer, with the word RECTAL etched on it. It had a re triangular top as well as a pear shaped bulb.
I was brought to my room by this nurse, a mid 30ish age woman. I was participating in a medical clinical trial. She questioned me on a number of health issues and inquired if I'd had a DRE in the last 5 years. I said "No". She told me she'd check w/ the doctor to see if I might need one. As she started to leave, she said, "Oh and when I return, I'll get your vitals". Before she left I asked if I was to get the DRE then could I first have my temperature taken rectally first as part of my vitals. She replied, "we'll see".
Returning a bit later, she had a tray with her and wheeled in a blood pressure set up. Sitting on the bed, I had my B.P. and pulse taken.
"You'll be getting ,the DRE she remarked and yes, I will take your rectal temperature."
She showed me the thermometer to be used, then instructed me to lay face down. I did. She lifted my robe over my hips, grabbed the waistband of my briefs and lowered them. She shook the thermometer down, held it up, read it, then dipped the bulb in a tissue w/ a dollop of Vaseline on it.
My cheeks were then parted by her thumb and index finger and my anal area was momentarily treated to a bit of coolness. The bulb of the thermometer gently touched my anal opening, and with her admonition, "breath in". I did and I felt her insert the thermometer into my anus and up into my rectum. Then she let my buttocks close. I laid there for 3 or 4 minutes as the thermometer registered. Then it was removed, my temperature noted.
A moment or two later on my side, my top buttock lifted, her gloved, well lubricated index finger, with the admonition of "breath in" again, entered my anal opening and continued up my rectum until she got to feel/examine my prostate.
One thing that I got out of the session, was that thermometer! She gave it to me.
I saw her again a few years later during another clinical trial, but the ear thermometers were in vogue and as good as it was to see and talk to her briefly, I was sad, no RT would be taken. We touched on that, and she said, "Times change". They do, but I'm still in possession of that thermometer. This occurred back in the early 80s.