Why Am I So Cold?

As he turned to go on, he spat speculatively. There was a sharp, explosive crackle that startled him. He spat again. And again, in the air, before it could fall to the snow, the spittle crackled. He knew that at fifty below spittle crackled on the snow, but this spittle had crackled in the air. Undoubtedly it was colder than fifty below—how much colder he did not know.

Many baby boomers might read this passage from Jack London’s “To Build a Fire” and nod knowingly. True, the character in the story is facing winter in the Yukon, while you may be padding around your living room with the thermostat turned up, but you have something in common. You’re both cold. As a correspondent put it recently: “Why do I want to sleep with my socks on?”

The explanation may be straightforward, if not comforting. You are getting older. And as people age, some find the cold harder to take, especially in their hands and feet.

Dr. Sharon A. Brangman, a professor of medicine at SUNY Upstate Medical University and a past president of the American Geriatrics Society, said increasing sensitivity to the cold could be a sign of a medical problem like hypertension or diabetes (though for some diabetics, the real danger is decreased sensitivity in their extremities that may leave them unaware of injury). Some drugs, like beta blockers, can decrease the heart rate, which can reduce the circulation of blood to hands and feet. Calcium channel blockers, used in hypertension, work by relaxing the blood vessels, which can increase heat loss. High cholesterol can reduce blood flow, too. And thyroid conditions can affect people’s ability to regulate their temperature.

But healthy people may also find themselves feeling colder than they used to. Among the reasons: a decrease in circulation as the walls of the blood vessels lose their elasticity and the thinning of the fat layer under the skin that helps conserve body heat. And as people age, their metabolic responses to the cold may be slower. Vasoreceptors, for example, may not be as quick to direct blood vessels to constrict to keep the body temperature up.

As it happens, studies have shown that older people are more likely to have slightly colder body temperatures than younger ones. But that does not necessarily mean that they feel colder. “We’re not sure how or if they’re related,” Dr. Jill Waalen, an epidemiologist at the Scripps Research Institute, said in an e-mail.

Instead, feeling colder seems to be a subjective response to the environment. And increased sensitivity to the cold does not pose a big health risk, or require any specialized medical treatment. “It’s like my mother always said: ‘Put on your sweater,’ ” Dr. Brangman said.

Or your socks.

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