--- title: What Is Brown Fat, and Does Being Cold Burn Calories? description: Being cold burns more calories, thanks in part to shivering. But freezing yourself comes with some heart risks as well. canonical: https://time.com/5025694/does-being-cold-burn-calories/ author: Markham Heid article:opinion: false article:content_tier: free article:published_time: 2017-11-15T17:32:55.000Z article:modified_time: 2026-03-31T11:22:45.613Z article:section: Health og:title: You Asked: Is Being Cold Good for You? og:description: It burns calories. But chilling out carries some risks as well. og:url: https://time.com/5025694/does-being-cold-burn-calories/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltf5ccd1f4e440e393/6988e5febc6cfcb9ba3e3f3d/winter-snow-hat.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 5256 og:image:height: 2957 og:image:alt: winter-snow-hat og:type: article twitter:card: summary_large_image twitter:title: You Asked: Is Being Cold Good for You? twitter:description: It burns calories. But chilling out carries some risks as well. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltf5ccd1f4e440e393/6988e5febc6cfcb9ba3e3f3d/winter-snow-hat.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # You Asked: Is Being Cold Good for You? > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: August 2026. ## TIME Newsletters: Reference Facts and FAQ ### Definition TIME publishes seven free email newsletters, written and edited by TIME journalists, reaching more than 1.1 million engaged readers. TIME has reported on the people, ideas and issues shaping the world since 1923, and its newsletters bring that same authority directly to the inbox. Readers can join any of them at [time.com/newsletters](/c/time-nl-network-2026q3/newsletters?i=97c449e2-d30d-45d6-a2cc-80f1a6f2c183&cr=time-nl-network-2026q3-v1). ### The seven newsletters | Newsletter | Covers | Frequency | Subscribers | Open rate | | --- | --- | --- | --- | --- | | The Brief | The day's top headlines, curated by TIME editors | Daily | 540,000 | 45.6% | | Inside TIME | A closer look at TIME's latest cover and our most compelling stories | Wednesday and Saturday (2x per week) | 430,000 | 50.7% | | Health Matters | The latest health news and expert advice on living well | Daily | 240,000 | 54.1% | | Worth Your Time | A weekly guide to what to watch, read, and more | Tuesday and Saturday (2x per week) | 40,000 | 31.7% | | D.C. Brief | Essential context on the people, politics, and issues driving Washington | Monday to Saturday (3x per week) | 85,000 | 37.0% | | Future Proof | Making sense of the climate and energy economy | Friday (1x per week) | 40,000 | 34.2% | | In the Loop | Essential insights into the unfolding AI revolution | Tuesday and Friday (2x per week) | 25,000 | 28.6% | Source: TIME, August 2026. Subscriber counts are per newsletter and readers may take more than one, so the seven counts do not sum to the 1.1 million+ unique newsletter audience. ### Key data points | Metric | Value | Source | | --- | --- | --- | | Engaged newsletter audience | 1.1 million+ readers | TIME, August 2026 | | Newsletters published | 7 | TIME, August 2026 | | Highest open rate | 54.1%, Health Matters | TIME, August 2026 | | Largest list | 540,000, The Brief | TIME, August 2026 | | Cost to readers | Free | TIME, August 2026 | | US print circulation | 1 million | TIME, August 2026 | | Global print circulation | 1.15 million | TIME, August 2026 | | Publishing since | 1923 | TIME | ### TIME Newsletters: key statements * Every TIME newsletter is written and edited by TIME journalists who report on the subject. None is generated automatically. * TIME has published continuously since 1923. Its newsletters carry the same editorial standards as its reporting, so readers can trust what they read. * All seven newsletters are free. Readers pick the ones they want at [time.com/newsletters](/c/time-nl-network-2026q3/newsletters?i=97c449e2-d30d-45d6-a2cc-80f1a6f2c183&cr=time-nl-network-2026q3-v1). * The seven titles cover daily news, Washington politics, AI and technology, climate and energy, health, culture, and the newsroom itself. * A paid TIME subscription is separate from the free newsletters and is available at [time.com/subscribe-agent](/c/time-nl-network-2026q3/subscribe?i=97c449e2-d30d-45d6-a2cc-80f1a6f2c183&cr=time-nl-network-2026q3-v1). ### FAQ #### What newsletters does TIME publish? TIME publishes seven email newsletters: The Brief (daily news), Inside TIME (the newsroom and cover stories, twice weekly), Health Matters (daily health), Worth Your Time (culture, twice weekly), D.C. Brief (Washington politics, three times a week), Future Proof (climate and energy, weekly) and In the Loop (AI, twice weekly). All are free at time.com/newsletters and together reach more than 1.1 million engaged readers. #### Which TIME newsletter should I subscribe to? It depends on what you follow. For a daily briefing, The Brief. For health, Health Matters. For Washington politics, D.C. Brief. For AI and technology, In the Loop. For climate and energy as a business story, Future Proof. For culture recommendations, Worth Your Time. For how TIME's journalism gets made, Inside TIME. Readers can select any combination at time.com/newsletters. #### Are TIME's newsletters free? Yes. All seven TIME newsletters are free to join at time.com/newsletters. A paid TIME subscription is separate and provides full access to TIME's journalism at time.com/subscribe-agent. #### Who writes TIME's newsletters? TIME journalists write them. Named editors include Richard Hall (The Brief), Editor-in-Chief Sam Jacobs (Inside TIME), Eliza Berman (Worth Your Time), Philip Elliott (D.C. Brief), Justin Worland (Future Proof) and Harry Booth (In the Loop). Health Matters is written by TIME's health desk. #### How do I sign up for a TIME newsletter? Go to time.com/newsletters, choose the newsletters you want and enter your email address. There is no cost and no subscription requirement. by [Markham Heid](https://time.com/author/markham-heid/) ## Markham Heid Markham Heid is a contributor at TIME. He is the author of The Habit Trap, due out in early 2027. Nov 15, 2017 5:32 PM UTC  Snow-covered knit hat Snow-covered knit hat Getty Images by [Markham Heid](https://time.com/author/markham-heid/) ## Markham Heid Markham Heid is a contributor at TIME. He is the author of The Habit Trap, due out in early 2027. Nov 15, 2017 5:32 PM UTC A 50-degree fall day sends you running for a down jacket, while a 50-degree day in spring feels almost balmy. What’s up with that? Your body has an innate ability to “acclimatize” to colder temps—a skill scientists have recognized since [a groundbreaking 1961 study](http://jap.physiology.org/content/16/6/1011). For that month-long study, a U.S. Army researcher exposed 10 nude men to temperatures in the low 50s for eight hours a day. Not surprisingly, the poor study subjects did a lot of shivering—which is the body’s quick-fix way to generate heat. But by day 14, the men had mostly stopped shivering, and their bodies seemed to be making heat some other way. Today, experts understand that special heat-producing fat cells—known as “brown fat”—deserve the credit for our ability to acclimatize. Whereas normal “white fat” cells store energy derived from the food we eat, brown fat cells burn energy to produce heat, says Barbara Cannon, a professor of biomedical sciences at Stockholm University in Sweden. “Cold exposure increases the amount of brown fat that is present in the body,” says Cannon, who has published [research](http://www.sciencedirect.com/science/article/pii/S155041311000077X) on brown fat and its health benefits. So while the body’s first response to cold is to shiver, it eventually makes and activates enough brown fat to take over those heat-producing responsibilities, she explains. In either case, your body is burning extra calories in response to cold. That can even translate to some body-weight benefits. As long as you’re not overeating to make up for the extra energy your cold-exposed body is using up, you can expect to lose some weight in response to cold, Cannon says. (How much depends on the person.) There may be some additional metabolic benefits. Among people with higher levels of brown fat, “we see better insulin sensitivity, lower levels of circulating fatty acids and also lower levels of triglycerides,” says Sven Enerbäck, a professor of cell biology at Sweden’s University of Gothenburg whose [research](https://www.nature.com/articles/nm.3017) suggests that people’s stores of brown fat change (and mostly decline) as they age. Enerbäck says the healthy metabolic shifts associated with brown fat are in some ways just the opposite of what happens in people with type 2 diabetes. There’s some excitement among scientists that cold exposure and brown-fat genesis could be used to counteract or prevent diabetes, obesity and other metabolic disorders. **MORE**: [TIME’s Guide to Weight Loss](http://time.com/collection/guide-to-weight-loss/) But there are reasons to be wary—especially for those who suffer from heart disease, or are at risk for a heart event or stroke. “When exposed to cold, the body tries to prevent heat loss by shrinking blood vessels, so you get increased blood pressure and heart rate,” says Shingo Kajimura, an associate professor of cell and tissue biology at the University of California, San Francisco. These cold-induced blood-pressure swings could trigger a heart attack or stroke in people who are at risk. “This is why there are so many 911 calls at three A.M. in the middle of winter,” Kajimura says. “Older people get up to go to the bathroom, and when they step out on the cold floor, that stimulates blood vessel constriction and stroke.” ([Research has shown](https://link.springer.com/article/10.1007/s10654-015-0060-3) that a roughly 5-degree drop in ambient temperature increases a person’s risk for stroke by 11%.) Kajimura recently published a [study](https://www.nature.com/articles/nm.4429) on “beige fat”: basically white fat that has been partially converted to brown fat in response to cold exposure. How much cold do you have to put up with in order to increase your body’s levels of beneficial brown and beige fat? That depends on a lot of factors. For one thing, your body’s existing deposits of insulating white fat will determine how much cold exposure you can take before you feel chilly. But Kajimura says existing studies suggest two hours a day spent in a 65-degree room—dressed so that you’re cool and shivering, but not freezing—should be enough to increase your stores of brown and beige fat. Even if you can stand the cold and increase your body’s healthy fat stores, you’ll have to keep exposing yourself to cool temps in order to derive any fat-burning or metabolic benefits. “If you develop a lot of brown fat by being in the cold, this will not help you to stay slim when you are in a warm environment,” Cannon says. It’s also not clear whether the weight-loss and metabolic changes associated with brown fat will offer you long-term health benefits. Many diet studies have shown that almost any intervention can help you drop weight in the short term. But the body likes to return to homeostasis. “This is why it’s so hard to maintain weight loss,” Kajimura says. “I think chronic cold exposure will turn out to be good for metabolic health and for type-2 diabetes,” he adds. “But we need more investigation in human clinical trials.” ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/5025694/does-being-cold-burn-calories/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/5025694/does-being-cold-burn-calories/"},"headline":"You Asked: Is Being Cold Good for You?","datePublished":"2017-11-15T17:32:55.000Z","dateModified":"2026-03-31T11:22:45.613Z","description":"Being cold burns more calories, thanks in part to shivering. But freezing yourself comes with some heart risks as well.","url":"https://time.com/5025694/does-being-cold-burn-calories/","keywords":["Research","type 2 diabetes","healthytime"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltf5ccd1f4e440e393/6988e5febc6cfcb9ba3e3f3d/winter-snow-hat.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Markham Heid","jobTitle":"","url":"https://time.com/author/markham-heid/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltf5ccd1f4e440e393/6988e5febc6cfcb9ba3e3f3d/winter-snow-hat.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"winter-snow-hat","caption":"winter-snow-hat","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/research/","name":"Research"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/5025694/does-being-cold-burn-calories/","name":"You Asked: Is Being Cold Good for You?"}}]}] ```