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How Does a Fan Work to Cool You Off?

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It feels almost intuitive that the moving air would help keep you cool. After all, that's what a breeze does and, in a pinch, waving a folder in front of your face on a hot day will provide a little relief. But since temperature is a feature of the molecular properties of a substance, the air itself isn't made any cooler by movement—it just makes us feel cooler when it blows by.

On a hot day—or on a not so hot day if it's "wind chill" you're talking about—moving air helps your body with the cooling off process. Humans lose heat—a necessity for thermoregulation—through conduction, radiation, convection, and evaporation. The final two are what account for fans' effects. On a hot day, your body sweats to lose heat through the evaporation of that moisture. In still air, that evaporation causes the area immediately surrounding your skin to reach body temperature and 100 percent humidity—rendering it essentially ineffective to continue the process. A fan, or a breeze, helps by replacing this hot, humid air with cooler, drier air that allows for more evaporation.

Similarly, even without sweat, our body loses heat to the surrounding air simply by convection. If our internal temperature is higher than that of the surrounding air, energy—and thus heat—is transferred. However, once again, in motionless air, this simply creates a boundary area of hot air around you. The breeze from the fan carries that hot air away and perpetuates the process, effectively cooling you off.

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Time-Restricted Eating: The One Simple Trick That Might Help You Lose Weight
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You’ve likely heard personal trainers or nutritionists say it’s important to eat breakfast right when you wake up to jump-start your metabolism and begin the day with your engine revving. But a new diet trend called time-restricted eating, which is basically a form of fasting in which you refrain from eating for several hours of the day, flips that thinking on its head: On this plan, you could be awake for several hours before you eat anything.

It might sound counter to conventional dieting advice (not to mention difficult to stick to), but research has found it can be an effective way to stay slim—even if you don’t restrict what you’re eating. Read on for more about the science behind this craze and whether it might be a good meal strategy for you.

THE BASICS

To follow a time-restricted diet (which is also known as intermittent fasting), you can continue eating the same foods you normally do, you just only eat them during a certain number of hours of the day. You start by restricting all eating to an 11- or 12-hour period—so, if you have breakfast at 8 a.m., you’ll have to set forks down by 7 or 8 p.m. You’re allowed to drink water, coffee, or tea (with no milk or sugar) during the fasting periods between bedtime and in the a.m., but you have to steer clear of ingesting anything else.

If you want to give it a shot, it’s a good idea to start slowly, advises Jaclyn Jacobsen, a nutritionist with the Vitamin Shoppe. Begin by fasting for about 12 hours of the day (including the time you sleep). Once you get used to it and it feels fairly easy, try dialing it back even further, allowing yourself to eat only 10 or maybe even eight hours of the day. “Theoretically, the longer you fast, the more fat you are burning for energy in the absence of glucose,” Jacobsen says.

THE BENEFITS

A few animal-based studies suggest that time restriction might be all that’s necessary to help you slim down. Recent research published in the journal Cell Metabolism, for instance, found that this rule can help you maintain a healthy weight—even if you cheat on the weekends. And the study also found that it didn’t matter what you eat: If you eat it during a small window of the day, you’ll still be slimmer than if you eat it at all hours.

In addition to helping you maintain a healthy weight, restrictive eating might also help you have less inflammation and lower your risk of diabetes, heart disease, and other chronic illnesses. Longer fasting periods and less eating in the evening may lower inflammation and risk of breast cancer as well, according to a study published in PLoS One.

It makes your body burn fat more efficiently, too, says Jacobsen: “When glucose is absent, the body will break down fat stores into free fatty acids for energy. This use of free fatty acids enhance fat burning as you are using stored fat for fuel.” And though it may seem contradictory, time-restriction can actually make you less hungry—by normalizing your body’s level of ghrelin (the "hunger hormone"). “Fasting helps the regulation of this hormone so we feel hungry only when we actually need to eat,” Jacobsen says.

And this is where the trainer's advice to "jump-start" your metabolism by eating breakfast takes a beating: “Much research has shown that your metabolic rate actually increases when fasting, so you burn calories more efficiently when you do start eating,” Jacobsen says. Your metabolic function won’t decrease significantly, she says, unless you go at least three full days without eating.

THE DRAWBACKS

Cutting back on the hours you’re allowed to eat might not come naturally. Some people will adapt easily and get used to eating during a small window of time after just a few days, according to Jacobsen, while others will take up to a month to fully adjust. And you might never feel fully acclimated.

Another big drawback: It might not get you the slim-down results you want. “Some individuals, especially women, are very sensitive to any type of hormonal changes in the body, so fasting may offer no additional benefit when compared to eating a whole-foods diet,” she says.

THE VERDICT

You’ll likely see better weight-loss results and feel better if you make healthier food choices in general, Jacobson says; whether you’re doing time-restricted eating or not, she recommends a diet consisting of about 80 percent whole foods (like vegetables, whole grains, and lean protein) and letting yourself indulge in treats 20 percent of the time.

So intermittent fasting might be worth a shot, but keep in mind that skipping midnight snacks or early-morning coffee with cream might not necessarily be ideal for you. “There is no ‘one size fits all’ when it comes to this concept or any other health-related concept,” Jacobsen says. “Nutrition is so individual, so what works for one group of people, may not work for others. It’s all trial and error.”

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What's the Correct Pronunciation of February?
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In the United States, the most common pronunciation is feb-yoo-air-ee. Both Merriam-Webster and American Heritage dictionaries consider the common pronunciation correct, along with the less common, more traditional standard feb-roo-air-ee.

This gets fans of the traditional standard all worked up. But the loss of the first r in February is not some recent habit propagated by lazy teenagers. People have been avoiding that r for at least the last 150 years, and probably longer than that. Given certain conditions having to do with word stress and the other sounds in a word, we simply do not like to have two r's so close to each other. The name for the linguistic process where one sound drops out because another of the same sound is too close to it is dissimilation, and it affects lots of languages.

Consider your pronunciation of the following words, and be honest about whether you really say the r's in parentheses: su(r)prise, gove(r)nor, pa(r)ticular, be(r)serk, paraphe(r)nalia, cate(r)pillar, southe(r)ner, entrep(r)eneur, p(r)erogative, interp(r)etation. Not everybody drops these r's, but at the same time, nobody seems to get too upset when they hear others do it.

There are, however, a few cases of r dissimilation that get people very worked up, namely, lib(r)ary and Feb(r)uary. Lib(r)ary attracts attention due to its association with commonly disparaged dialects. Feb(r)uary only seems to attract attention when someone asks what the proper pronunciation should be.

Here's a little help from the (parody!) guide Pronunciation Manual:

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