How the body makes heat in the cold, and what modern research says about everyday foods and traditional practices

On a chilly morning, the first response is usually practical: a thicker jacket, a hot drink. But if exposure lasts longer than a few minutes, external insulation alone is not enough. The body has to generate extra heat internally to keep its core temperature stable, and the energy for that heat comes from the food and drink one has taken in. The everyday phrase "feeling cold" usually masks this internal furnace at work.

This is why ordinary readers often ask questions that sound simple but reach into physiology: what should I eat when my hands are always cold, is being cold-sensitive a sign of a certain body type, do particular herbs warm people up? Those questions belong to a long tradition of linking the weather outside with what one eats and wears. The 2026 review responds to that same instinct from a different angle, sorting potential thermogenic substances into nutrients, traditional Chinese medicine, TCM extracts, and dietary functional factors. The everyday question "what should I eat in the cold?" is, in modern form, the question "which ingested substances might influence thermogenic pathways?"

Linking climate to food and dress is not new. The Lingshu, in its fifth-roller discussion of the origins of illness, lists wind, rain, cold, and summer heat alongside emotion, diet, and dwelling as factors that shape human illness. Cold and warmth appear at the top of that list, sitting next to dietary and behavioral choices. The structural similarity between that ancient framing and the modern review's pairing of cold exposure with dietary substances is one of the reasons a curious reader can find both pages interesting at once.

The review's findings can be read in layers. The first layer is foundational: in mammals, a constant body temperature is maintained for survival in cold environments, primarily through the activation of thermogenic mechanisms. This is the physiological backdrop against which everything else is set.

The second layer is the typology of heat-making. The review outlines the primary thermogenic responses to cold exposure, including shivering thermogenesis (ST) and non-shivering thermogenesis (NST), and emerging thermogenic pathways. Two points are worth holding onto. First, shivering and non-shivering are framed as the main categories, not as competing claims. Second, the explicit mention of "emerging" pathways tells the reader that researchers themselves see gaps in the picture, and that newer routes are still being drawn in.

The third layer is the catalog of substances. The review discusses the mechanism of action of various thermogenic substances, including nutrients, traditional Chinese medicine (TCM), TCM extracts, and dietary functional factors. The take-away for a non-specialist is that the review treats the entire dietary intake as a research surface, not just pills or supplements.

The fourth layer is forward-looking. The review closes by saying it provides a theoretical foundation for developing cold-resistance preparations with minimal side effects. That sentence is an outlook, not a verdict: it is the authors telling the field where the work might lead, not telling a reader what to consume. The careful reader should treat every statement about "nutrients," "TCM," or "dietary functional factors" in this review as a description of what has been studied, not as a recipe.

Translating the terminology, shivering thermogenesis is the body's loud furnace: muscles contract rapidly, chemistry becomes heat, and the person visibly trembles. Non-shivering thermogenesis is quieter. It often involves brown fat tissue and mitochondria that release energy as heat even when the body is not moving, providing a slower, steadier warmth. When the review talks about "emerging" pathways, it is pointing to routes that researchers believe exist but cannot yet describe in full. The interesting question the review then asks is whether everyday substances, such as nutrients, traditional herbs, or compounds purified from them, can nudge any of these pathways.

It is important to keep distance between "described in research" and "useful for me." The review can tell a reader which substances have been studied in connection with thermogenesis, but it does not, and cannot, tell a particular person what to eat, how much, or whether doing so is appropriate. This is why the present article avoids food lists and dosages throughout. A 2026 review is a snapshot of where the science is, not a prescription pad.

Stepping back, the parallel with the Lingshu is worth holding lightly. The sixth-roller passage on food, clothing, and temperature reads, in its classical line: "飲食衣服，亦欲適寒溫，寒無悽愴，暑無出汗。食飲者，熱無灼灼，寒無滄滄，寒溫中適，故氣將持." The emphasis is on suitability: do not let cold reach the point of shivering discomfort, do not let summer heat force sweat, and in food and drink avoid both scorching heat and icy chill. The classical text is not prescribing a warming food; it is prescribing moderation and timing. The modern review breaks cold adaptation into molecular pathways; the classical passage speaks of the body holding its qi steady through balanced exposure. The scales differ, and the vocabularies differ, yet both invite the reader to think about the body and the environment as a pair rather than as separate things.

Several things are described in the review but not settled by it, and a careful reader should keep them apart. The review states that in mammals, a constant body temperature is maintained for survival in cold environments, primarily through the activation of thermogenic mechanisms, and it discusses the mechanism of action of various thermogenic substances, including nutrients, traditional Chinese medicine (TCM), TCM extracts, and dietary functional factors. Both sentences describe a research landscape; neither certifies that any specific substance is appropriate, effective, or safe for an individual in cold conditions.

Three cautions follow. First, "studied" is not the same as "recommended." A substance appearing in a review's catalog means researchers have investigated it, not that the review endorses taking it. Second, "emerging thermogenic pathways" is a marker of incompleteness, not of readiness. Newer routes are still being mapped, and any practical claim built on them would be premature. Third, the classical comparison must not be overread. The Lingshu's principle of matching food and clothing to seasonal temperature, and the modern review's catalog of thermogenic substances, are not in a one-to-one relationship. They are two different ways of organizing a question, and saying that the modern review "validates" the classical principle would go beyond both texts.

許多人在天冷時都會好奇：身體是怎麼自己「發熱」保暖的？日常飲食或傳統做法，能不能在這件事上幫上一點忙？如果讀者沒有生理學背景，不妨把「產熱」（thermogenesis）想成身體像一座小暖爐，會依環境條件點燃不同的燃料與開關。

這篇 2026 年發表的綜述開宗明義指出，哺乳類之所以能在寒冷中維持恆定的體溫，主要仰賴產熱機制的啟動。接著，作者把主要反應分成兩大類：第一是顫抖性產熱（shivering thermogenesis，簡稱 ST），也就是我們熟知的發抖，那是骨骼肌不自主收縮、把化學能轉成熱能；第二是非顫抖性產熱（non-shivering thermogenesis，簡稱 NST），以及近年正在被研究的新興產熱路徑——後者多半發生在棕色脂肪組織等部位，透過粒線體「洩漏」能量直接產熱，不必靠肌肉抖動。換言之，身體其實備有一套雙軌的制暖系統：緊急時顫抖即時加熱，長期則由脂肪組織接手細水長流。

除了機制本身，綜述也回顧了所謂「產熱物質」的範疇，包括營養素、中藥、中藥萃取物，以及飲食中的功能性成分。作者的用意，是為日後研發低副作用的抗寒製劑提供理論基礎。對一般讀者而言，這段提醒我們：食物並非只能「填飽」，某些成分確實可能參與體溫調節的生化舞台；不過綜述本身屬於學理回顧，並未替讀者開立處方，也不等於替讀者背書任何單一食材的即時效果。