Day of rest. Went to church. Felt better. The fever was gone. Sarah questioned if I was healthy enough to go home teaching after church. To prove myself I took my temperature, and it was 97.0 F. To prove myself further I put on an HRM to measure resting heart rate. At first it was showing 75 or so, which would have meant I was sick. But I know what resting HR of 75 feels like, and I was 100% sure it was not 75. So I counted it manually and it was 52! Then I figured the problem was the contacts were too dry. After wetting them sufficiently I started getting readings that were consistent with the manual count and the way I felt. HR fluctuated between 47 and 57, and spent most of the time in 50-52 range. Which is my normal healthy range.
Moral of the story - know when to question your instruments.