How Accurate Are Digital Thermometers?

I wanted to know my temperature, so I would know when I have a fever.  I was also curious how my temperature compares to "normal" people.  

But first, I had to figure out how accurate my digital thermometer is.

Accuracy is how close a measurement is to the true value; precision is how much variability there is in repeated measurements.  The thermometer says it is accurate to within +/- 0.2 F, but I have no way to test that because I have no other measurement of my temperature to compare it with.  I can test the precision by taking multiple readings in a row.  This usually yields the same number, indicating that the precision is very good (i.e. low variability).  However, sometimes, depending on how I hold the thermometer, the readings can vary by as much as 0.4.

What is my normal temperature?  

To test this, I took my temperature over 10 days in April, 2024.  I took 48 readings, a total of 3-4 for each hour of the day.  For each reading I lay down for a minute and then put the thermometer in my mouth, as far back under the tongue as possible.  Each reading took 90-120 seconds, so this effort included more than an hour of total time spent taking my temperature.

My average temperature is 97.4, almost a full degree less than the widely-quoted population average of 98.2.  Standard deviation is 0.6 degrees, so 68% of the time my temperature is between 96.8 and 98.  This variability include any precision variability in the thermometer.

My temperature usually reaches a minimum in the morning, rises to a maximum is in late afternoon / early evening, and then begins to fall before bedtime.  My highest temperatures were recorded after exercise, doing chores, eating a warm/fatty dinner, and lying in the sun.  Minimum temperatures were recorded lying in bed, after exercise, and after breakfast.  

Teachers and What I Learned

This post has been a work in progress since I realized in 2007 that the university couldn't teach me what I needed to learn.  Since then, I've worked on farms and learned ecology from teachers in the field.  But it took me a long time to learn that the real lessons I needed were those that could heal my own body.

Foundation Pose by Eric Goodman - taught me how to load posterior chain, how to bend from the waist. His plank taught me how to activate abs and what neutral spine really means.

Alan Thrall taught me how to deadlift. I went from not being able to do it or hurting myself to lifting regularly.

Brian Mackenzie and Dr. Park taught me to nose breathe during aerobic exercise, and all the time, and that I'm naturally a mouth breather.  Maybe that's why I have sleep apnea.  I never realized it was normal to breath though the nose. 

Diet
Diet gurus, yoga teachers: never taught me anything and may (raw diet) have sent me down the wrong path.  Omnivore's dilemma (eat whole foods, mostly plants) is probably best.  Paul Pitchford has a lot of really deep diet advice, unfortunately it doesn't work for me.  Neither do blood type diets, etc. 


Other Teachers
Headspace app taught me to meditate. But Andrew Weil's 4-7-8 breath works just as well now that I have a few key concepts.

Happy body book by Jerzy Gregorek taught me that relaxing after exercise is as important as muscle tension, and the importance for spine health of hanging (traction) after compression on the spine.

Paval Tsatsouline also teaches that strength is learning to completely tense and then relax muscles.

Getting an inversion table teaches how to stretch spine and soas muscles. 

Slack line teaches balance.  "Gorilla feet" Vibram 5-finger shoes help with balance and teach what is correct shape of the foot.  Altra shoes are also good for this.

I learned a lot in the last 5 years!