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Why do our hairs stand on end when we're cold? © Acute Graphics

Why do our hairs stand on end when we're cold?

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Piloerection is hair-raising business...

Asked by: Toby Graham, Shrewsbury


When we’re chilly, tiny muscles contract at the base of each hair to make them stand on end, distorting the skin to create goosebumps. All mammals share this hair-raising trait, called piloerection, of using hair or fur to trap an insulating air layer. The process may have helped to keep our hairy ancestors warm, but today’s human body hair is too fine to be of much use. Shivering does a far better job of warming us up through rapid muscle contractions.

Why do women feel the cold more than men? © Getty Images


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Dr Emma Davies is a science writer and editor with a PhD in food chemistry from the University of Leeds. She writes about all aspects of chemistry, from food and the environment to toxicology and regulatory science.


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