With every cold snap, millions utter the phrase "I feel cold in my bones" as if it were an undeniable truth. But science says something different, confirming that bones are affected by cold in ways we can't imagine.
It is known that the human body is designed to function efficiently at a temperature of approximately 37 degrees Celsius.
But our extremities, such as our hands and feet, can be up to 6 degrees colder. Several factors influence how cold we feel, including age, gender, and health status.
Older people feel the cold more than younger people, and women are more sensitive to the cold than men.
Surprisingly, bones themselves don't feel cold the way we do; they lack the temperature-sensitive receptors found in skin. This makes sense because bones are buried under layers of muscle, tissue, and skin.
So, where does this deep feeling of cold come from?
A study in anatomy reveals that bones are not completely isolated from the effects of cold; they are affected by cold in indirect ways, through the surrounding tissues, changes in blood circulation, and even vitamin D deficiency in winter.
The outer covering of the bone, known as the periosteum, contains a network of nerves that sense changes in temperature, especially cold. These nerves can send signals similar to pain signals, which we might interpret as a sensation of cold in the bones.
Most importantly, prolonged exposure to cold for weeks can actually affect bone health, reducing its length, thickness, and mineral density.
Other tissues are the most affected
The tissues surrounding the bones are most affected by weather changes. The synovial fluid that lubricates the joints thickens in cold weather, making movement more difficult and uncomfortable, especially for those with arthritis. Tendons and ligaments also become stiffer, requiring muscles to work harder to move the bones and reducing range of motion.
At the same time, blood flow to the extremities decreases, a protective mechanism to maintain the body's vital organs at rest. This reduction in blood flow increases tissue shrinkage and intensifies the feeling of stiffness.
Another equally important factor is sunlight. In winter, especially in the Northern Hemisphere, the days become short and the sky gray. In London, for example, the average sunshine duration in December is only 3.4 hours.
Insufficient sun exposure leads to a deficiency in vitamin D, which is essential for bone health. Research indicates that a lack of this vitamin increases pain sensitivity, particularly muscle and bone pain, and is also linked to increased anxiety and depression, which in turn alter the body's tolerance to temperature.
In conclusion, the saying "I feel cold in my bones" is not just a metaphor, but an accurate description of complex reactions that occur in our bodies with a drop in temperature.
The good news is that there are simple ways to deal with the cold wave, including eating extra calories, which gives the body fuel to heat up, wearing multiple layers of clothing that trap warm air close to the body, and constant movement which generates extra heat.
