Between 1:55 PM and 2:01 PM my electronic thermometer went from 96.9 F to 97.6 F to 98.2 F to 98.8 F. This is plausible, as I had been at the gym from 12:45 to 1:20, doing 5 minutes of cardio (some slow elliptical, some 15-second bursts of speed, some 30-second medium-paced intervals) followed by 25 minutes of weights (quick positives followed by slow negatives; did arms, back, chest, legs). I got home and took a shower, then took my temperature immediately. I did feel like I was heating up in that five minute interval, numbers or no numbers.
Other conditions: I drove home from the gym without AC but with the vent running; it was a semi-pleasant 76 F and 55% humidity outside. I had a good 8 or more hours of sleep last night, woke up hungry, but not hungry enough to eat. Breakfast (at about 10 AM) was two “turkey patties” with a large avocado, some blackberries, walnuts and pecans. And two to four delicious cups of coffee. I had nothing else to eat before working out.
At 2:10 PM my mercury thermometer is reading 98.7 F. (It held steady through 2:15 PM.) Dang, I have to work hard to get a (wanna be) “normal” temperature!!