Differences between readings, when use distinct thermometers

I took my rectal temperature 30 minutes ago. For this I use two rectal thermometers. I inserted the first rectal thermometer in my ass, and I kept it in for 5 minutes. When I took it off, the first rectal thermometer show 37.5 degrees celsius. I inserted the second rectal thermometer in my ass, as well I kept the thermometer in for 5 minutes. And when I read it, the thermometer show 37.1 degrees celsius. I was surprised by this difference between them and I took my rectal temperature again with both of them. For this time the first thermometer reading was 37.5 degrees celsius , like first time. And the second thermometer show 37.4 degrees celsius. 😃

Did it ever happened to any of you?

Your body temperature can change a few degrees within minutes.

I have to agree with JJM. Your body temperature can change in minutes. It can change while laying under the covers in bed or being in the shower. It can also change when you are hot and sweaty as well.

I have noticed different reading when taking rectal temperatures too. I took my rectal temperature with a glass mercury thermometer and had a rectal temp of 99.4. Then I used a digital thermometer right after the first reading. The digital thermometer registered 98.6 rectally- almost a full degree lower. I also notice differences right after exercising as the reading is higher. Morning readings are usually lower and night time readings are higher by one degree.