Are You More ‘Deficient’ If You Fear Cold or Heat?

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There is such a “joke” online:

Although it’s a joke, in real life, “being afraid of cold” and “being afraid of heat” can automatically make people associate with “kidney deficiency,” “yang deficiency,” and “yin deficiency” , as if any difference in body temperature perception from others must mean there’s a problem with your health.

Health product companies seize on this anxiety, using phrases like “warming supplementation” and “nourishment” to package “being afraid of cold” and “being afraid of heat” as health crises that must be resolved immediately.

But is this really the case? Today, let’s discuss this issue from the perspective of evidence-based medicine.

What exactly is “deficiency”?

In the diagnostic system of modern medicine, there is no concept of “deficiency.”

The so-called “kidney deficiency,” “yang deficiency,” and “yin deficiency,” they are not a clear medical diagnosis, but rather a vague description by traditional medicine of a series of ambiguous symptoms.

It’s like using the word “uncomfortable” to describe all diseases—the headache is uncomfortable, diarrhea is uncomfortable, and insomnia is also uncomfortable. But you can’t think they are the same disease just because they are all called “uncomfortable,” and you can’t treat them with the same medicine.

“Deficiency” follows the same logic; it is often a mixed description of the following conditions:

These conditions have completely different causes, mechanisms, and treatments, yet they are all packaged together by the term “deficiency.”

The concept of “deficiency” is so deeply rooted for two reasons: it is vague enough to explain everything, and commercial marketing deliberately amplifies it— as long as you say you are tired, afraid of the cold, afraid of the heat, or lack energy, someone will tell you “this is deficiency, you need to supplement.” Essentially, it’s about selling anxiety, not medicine.

So, when someone tells you “you are afraid of the cold or heat because you are deficient,” it essentially means nothing. It’s like a doctor telling you “you are sick because you are unhealthy,” which is a true but useless statement.

How does the human body perceive cold and heat?

Back to the topic of “being afraid of cold and heat,” each of us has an “intelligent thermostat system” built into our bodies.

So why do some people react strongly to temperature changes, while others hardly feel anything?

The answer lies in whether the body has enough “executive ability” to complete these regulatory actions after the hypothalamus issues the command. And among these, the core execution link is the heat production capacity.

If you compare the human body to a car, the hypothalamus is responsible for “stepping on the gas and the brake,” then the basal metabolic rate determines the engine speed of this car.

The higher the engine speed, the faster the fuel consumption, and the more heat is produced; the lower the speed, the more limited the heat production capacity is.

This also explains a common phenomenon: whether you are afraid of the cold or heat largely depends on how fast your “engine” usually runs. .

People with a high basal metabolic rate, such as those with hyperthyroidism, are like an engine running at a high speed for a long time, continuously producing heat, so they are more likely to be afraid of heat and sweat a lot; while people with a low basal metabolic rate, such as those with hypothyroidism, are more like an engine running at a low speed, with insufficient heat production, and naturally more likely to be afraid of the cold and have cold hands and feet.

But that’s not the end. Even if your “engine” is running normally, if the heat cannot be effectively delivered to where it needs to go, the body’s temperature sensation will still be problematic.

This involves the third key link in body temperature regulation— peripheral circulation.

To continue with the car analogy: no matter how well the engine produces heat, if the ventilation pipes responsible for delivering warm air are broken, the cabin will still not be warm. In the human body, these “ventilation pipes” are blood vessels. .

When peripheral blood vessels constrict, the blood flow to the extremities such as hands and feet decreases, and heat transferring decreases, making people feel cold in their hands and feet; when the blood vessels dilate and the blood flow is sufficient, heat is more easily dissipated, making people feel hot or even sweaty.

Caption: During intense physical activities, such as skiing (a) or running (c), dermal blood vessels dilate, and sweat secretion increases (b). These mechanisms prevent the body from overheating. In contrast, to cope with low temperatures, dermal blood vessels constrict to minimize heat loss (b).

This is also why many women experience a seemingly contradictory sensation: the body does not feel cold, but the hands and feet are always cold. This is not a “poor constitution,” but rather the peripheral blood vessels are more sensitive to cold stimuli and are more likely to constrict.

So, the human body’s perception of cold and heat, is the result of the hypothalamus’s regulatory commands, the heat production capacity of basal metabolism, and the heat transport and dissipation of peripheral circulation, all three working together. .

It is for this reason that being afraid of cold or heat essentially reflects the differences in the way the body’s temperature regulation system works, rather than a simple issue of “deficiency.”

When should you pay attention?

As mentioned earlier, being afraid of cold or heat does not necessarily mean “deficiency,” but this does not mean that all fear of cold and heat can be ignored. The key is not whether you have this feeling, but whether it is a normal physiological difference or a signal of disease from the body.

In clinical practice, most cases of feeling cold are physiological , such as low body fat, less muscle mass, long-term insufficient heat intake or dieting, sedentary lifestyle, or simply wearing less, low environmental temperature. The fear of cold in these people is not a disease, nor is it related to “deficiency”; it is just a normal difference in physique.

However, if feeling cold is accompanied by the following manifestations, it is necessary to be vigilant :

Common causes include hypothyroidism, anemia, malnutrition, or peripheral vascular circulation disorders. The essence of these conditions is insufficient heat production or limited heat transport, not something that can be simply solved by “supplementing.”

Compared to feeling cold, feeling hot deserves more of our attention.

Many people think that feeling hot represents good metabolism and strong vital energy, which is actually a common misconception.

From clinical experience, pathological causes of feeling hot often progress faster and pose higher risks.

Of course, there are also situations where feeling hot does not need to be worried about, such as having a high basal metabolic rate, large muscle mass, just after exercising or eating, high environmental temperature, or wearing too much clothing.

It can be seen that, feeling cold and feeling hot are not the issues themselves; what truly matters is whether there are accompanying abnormal signals and whether these changes are “recently appeared and continuously worsening.”

In conclusion, from the perspective of evidence-based medicine, feeling cold and feeling hot are neither equivalent to the body being “deficient” nor simply a sign of the body being “healthy.” They are merely signals emitted by temperature regulation and metabolic status, which require consideration of an individual’s physique, activity level, hormonal status, and whether there are other accompanying symptoms to make a reasonable judgment.

What we truly need to pay attention to is never the appearance of “feeling cold” or “feeling hot,” but whether there are potential health issues hidden behind them, such as thyroid function abnormalities, anemia, or cardiovascular-related diseases. .

So, stop being fooled by vague and general concepts like “kidney deficiency,” “yang deficiency,” and “yin deficiency.” Our bodies are not that fragile, nor are they that “deficient.” Understanding ourselves scientifically, rationally viewing differences, and seeking medical attention promptly for abnormalities is the truly responsible attitude towards health.

Disclaimer: The article is intended to provide general health information. For personal medical issues, please consult a doctor. To republish the article, please contact: medicine@distinctclinic.com.