2021年2月3日 星期三

Why Your Kid Wears Shorts in Winter

While you freeze in cold weather, they have a secret weapon.

Why Your Kid Wears Shorts in Winter

By Jessica Grose

Dani Choi

The past three weekends, I have found myself shivering on the concrete of local playgrounds, because of my least favorite pandemic-related cultural change: outdoor children's birthday parties in subarctic temperatures. I never thought I would miss the acrid smell of the dirty carpet at Brooklyn's finest indoor bounce house emporium and mediocre pizza dispensary, but I really, really do. At least I didn't have to wear a parka and two sweaters inside.

Despite at least two more months of frigid weather here in the Northeast, I will persist, because my kids are so happy at these birthday parties — and they are also not cold. Their little heads get sweaty under their hats and they end up unzipping their jackets, as my husband and I watch, huddled together for warmth.

Part of the reason they're not cold is obvious: They don't stop moving. "They jump up and down while we are just standing there," said Dr. Francesco Celi, chair of endocrinology, diabetes and metabolism at Virginia Commonwealth University. But there's also an anatomic reason that kids don't feel as cold as adults tend to, and it has to do with the amount of "brown fat" that babies and children have.

Brown fat is "a specialized fat, whose primary role is to generate heat," said Dr. Michael Symonds, professor emeritus at the University of Nottingham in England, who has studied brown fat's role in energy balance. A gram of brown fat produces 300 times more heat than any other tissue in the body, Dr. Symonds said.

It is concentrated in the neck area, and it starts generating heat when babies are born to help them adapt to the weather outside the womb. Infants need this highly efficient little internal furnace because they don't have enough muscle mass to shiver, which is an action that helps regulate body temperature for children and adults.

ADVERTISEMENT

"Brown fat is one of the critical mechanisms for the survival of newborns," Dr. Celi said. It also plays an important role for hibernating animals, as it helps them stay warm while they are asleep, and they use white fat — a less heat-efficient fat — for fuel. As the science writer Roxanne Khamsi put it on Twitter, brown fat helps you produce heat, while white fat just makes your jeans stop fitting.

The proportional amount of brown fat a person has decreases as they get older, Dr. Symonds explained, which is part of why adults feel colder than children seem to, and why you're always fighting with your 8-year-old who refuses to wear a hat. Though he was careful to point out that the perception of cold is fairly complicated, and brown fat is only one part of it. For example, women are generally thought to have more brown fat than men do, Dr. Symonds said, though women tend to be more sensitive to cold (which is why women sometimes need a blanket to combat office air conditioning).

Brown fat is also not static. You can build up your brown fat by spending more time in the cold. A study of Finnish lumberjacks was the first to find that outdoor workers who spend time in the cold have more brown fat than office workers, and Dr. Celi has done research that shows sleeping in cooler temperatures (66 degrees, in his study) may also increase your levels of brown fat.

So, I guess the good news is that if I keep going to these birthday parties, my body might adapt to the cold. Or, maybe I just need to invest in one of those wearable sleeping bags.

ADVERTISEMENT

P.S. Follow us on Instagram @NYTParenting. If this was forwarded to you, sign up for the NYT Parenting newsletter here.

Want More on the Science Behind Your Kid?

Tiny Victories

Parenting can be a grind. Let's celebrate the tiny victories.

To prevent my toddler from opening the spice drawer, we tell her the spices are sleeping. This also miraculously works for the clothes in the dressers. Shhh! — Dana Palmer, N.Y.C.

If you want a chance to get your Tiny Victory published, find us on Instagram @NYTparenting and use the hashtag #tinyvictories; email us; or enter your Tiny Victory at the bottom of this page. Include your full name and location. Tiny Victories may be edited for clarity and style. Your name, location and comments may be published, but your contact information will not. By submitting to us, you agree that you have read, understand and accept the Reader Submission Terms in relation to all of the content and other information you send to us.

Need help? Review our newsletter help page or contact us for assistance.

You received this email because you signed up for NYT Parenting from The New York Times.

To stop receiving these emails, unsubscribe or manage your email preferences.

Subscribe to The Times

Connect with us on:

facebooktwitterinstagram

Change Your EmailPrivacy PolicyContact UsCalifornia Notices

The New York Times Company. 620 Eighth Avenue New York, NY 10018

沒有留言:

張貼留言