Guides
Body Temperature and Metabolism: The Speedometer Idea
August 30, 2026 · Wilson's T3 Editorial
Strip away the protocol and the controversy and Dr. Wilson’s work rests on one idea: that body temperature is not a symptom of metabolism but a direct readout of it — a speedometer. Everything else follows. This guide collects the passages where he makes that argument, from the physics analogy to the mouse study to the Siamese cat, so a reader can judge the foundation before the building.
The speedometer
The body temperature is not just a good measure of the metabolic rate, it’s an exact measure. A thermometer is literally a speedometer. You’ve noticed that as you start to boil water, the vapor speeds up until eventually, the water begins to boil, and as you heat the water more it reaches a “rapid” boil. That’s because the temperature of the water is proportional to the speed of the molecules. That’s physics. When your body temperature is higher, it means that the molecules in your body are moving faster. Period. The speed of your molecules depends on your metabolic rate. Thus, the temperature is a perfect measure of the metabolic rate.
— How to Check Your Body Temperature for WTS
The mouse
His favourite piece of evidence for the claim is a physiology experiment:
A group of scientists inserted a thermometer sensor into the abdomen of a mouse and measured its body temperature continuously over a 24 hour period (dark line of readings in the diagram below). At the same time, they measured how much oxygen the mouse consumed out of the air (a difficult but direct measure of the metabolic rate)(red line of readings in the diagram below).
Notice how the two lines of readings are mirror images of one another! The only difference is that the temperature rises shortly after the metabolic rate increases (just as the temperature of the water on your stove rises shortly after you turn up the heat on the burner). It’s obvious from this diagram that no thyroid blood test will ever track the metabolic rate as closely as the body temperature does.
— How to Check Your Body Temperature for WTS
The diagram is on that page. The last sentence is the leap from physiology to his clinical position, and it is where the critics get off.
Why a degree matters: enzymes
The book builds the biochemical case from the ground up:
All the physical processes and even the mental processes that take place in our bodies are influenced or made possible by chemical reactions. The metabolism is basically the sum of all the chemical reactions that take place in the body. People use the term metabolic rate to indicate the rate at which these chemical reactions take place.
The shape of an enzyme also depends on its temperature. When enzymes get too warm, they get too loose. And when they get too cold, then they get too tight. When they are just the right temperature, then they are just the right shape and the chemical reactions that they catalyze take place at the optimal rate and with the most ease. When the temperature is too hot, too cold, or unsteady, the enzymes will spend less time in their optimal shape which simply translates into having a less than optimal metabolism.
— Body Function Dependent On Body Temperature, the book
The epoxy image he uses for what a catalyst is:
For example, when one uses epoxy glue to make a repair, it is necessary to mix the two parts together before it can be used. One part is the resin and the other is the hardener. Separately, they are useless as glue because they will not harden. But when the hardener is added to the resin, a chemical reaction takes place enabling the glue to do what it is designed to do. Here the hardener is acting as the vital catalyst. In the same way, if it were not for the important catalysts of the body known as enzymes, the body could not survive.
— Body Function Dependent On Body Temperature, the book
The cat
An interesting example of how this works can be seen in the Siamese Cat. Its coloring depends upon the production of a certain pigment which is the result of a chemical reaction that depends upon a particular enzyme. Since the function of this enzyme depends on its temperature, the chemical reaction will only take place when the temperature is just right. Interestingly, the only places where the temperature is cool enough for the chemical reaction to take place are found in the cat’s extremities. These are the coldest parts of the cat and include the cat’s paws, tip of the tail, tips of the ears, and the nose and mouth area of the face. That’s why these parts are dark with the rest of the cat being light colored, and thus the characteristic markings of a Siamese Cat.
— Body Function Dependent On Body Temperature, the book
It is the best-known passage in the book because it makes a small temperature difference visible.
The continuum argument
This is the step that turns “fever is dangerous” into “a degree low matters”:
So we can see that temperature plays a major role in the function of enzymes. For this reason, doctors have long been concerned about patients having very high fevers. If the temperature goes too high, the patient’s brain enzymes can denature (get malformed) which can cause delirium and can even be life-threatening. Doctors have also long been concerned with the opposite extreme when the body temperature is too low (hypothermia). This is equally dangerous and also can be life-threatening. It is difficult to understand why we have been very concerned about extremely high or extremely low temperatures, but frequently appear to not even consider the effects of milder aberrations in body temperature.
— Body Function Dependent On Body Temperature, the book
A problem in the thyroid system can result in a low metabolic rate, a low temperature, and depression. Thus, the connection between thyroid and depression is a low body temperature. However, people can have normal thyroid gland function and still have low body temperatures and depression.
What the argument does and does not establish
It establishes that temperature tracks metabolic rate closely — the mouse study is real physiology — and that enzyme function is temperature-dependent, which is textbook. It does not by itself establish that a temperature averaging 97.5 causes any particular symptom, or that raising it with T3 corrects the symptom; those are the clinical claims, and the record behind them is small (an eleven-patient report and a clinical-experience paper, described on the author page). The objection hub sets out where the ATA and others part company with him, which is precisely at that step.
If you want to test the foundation on yourself, the measurement is the same one the whole site uses: how to take your temperature and what the numbers mean. The full chapter is Body Function Dependent On Body Temperature; the temperature hub has the articles.
This is a reader’s guide compiled from Dr. Wilson’s published writing; every quotation is his and links to its source. It is not medical advice.