Temperature does more than influence comfort — it directly affects metabolism.

The human body is designed to maintain a remarkably stable internal temperature, typically around 37°C (98.6°F). When surrounding conditions become cooler, your body must work harder to preserve that balance.

This process requires energy.

One mechanism involved is called thermogenesis — the production of heat.

When exposed to mild cold, the body activates specialized fat tissue known as brown fat (or brown adipose tissue). Unlike regular body fat, which stores energy, brown fat burns calories to generate heat.

Think of it as the body’s internal furnace.

While brown fat is more abundant in infants, adults retain some — and research suggests it can still contribute to energy expenditure.

Shivering is the more obvious response to cold, involving rapid muscle contractions that create warmth. But before shivering begins, the body often relies on non-shivering thermogenesis — a quieter metabolic adjustment.

This doesn’t mean you should seek extreme cold. The benefits appear most relevant in mildly cool environments, not uncomfortable ones.

Interestingly, modern climate control has reduced our exposure to temperature variation. Heated buildings in winter and strong air conditioning in summer keep us within a narrow thermal zone.

While convenient, this stability may reduce opportunities for the body to engage natural thermoregulatory processes.

Some researchers describe this as living in a “thermal comfort bubble.”

Allowing slight temperature variation — such as cooler indoor settings or seasonal outdoor exposure — may help maintain metabolic flexibility.

But comfort still matters. Chronic cold stress is not the goal.

Instead, think in terms of gentle environmental diversity.

Beyond metabolism, cooler temperatures can influence sleep as well. The body naturally lowers its core temperature in the evening to initiate sleep, which is why many people rest better in slightly cooler bedrooms.

Temperature, metabolism, and circadian rhythm are closely intertwined.

Of course, energy balance is complex. No single factor determines metabolic health. Movement, nutrition, sleep, and genetics all contribute.

Still, temperature reminds us of something important:

The body is adaptive.

It is constantly making micro-adjustments to maintain equilibrium.

And sometimes, that adaptation quietly requires more energy than you might expect.

Your environment doesn’t just surround you — it interacts with your biology.