CLOSE
iStock
iStock

Why Does Having a Fever Make You Feel Cold?

iStock
iStock

During fever, why do we feel cold when our body temperature rises?

Nicole Van Groningen:

Anyone who has ever had the flu knows that fever isn’t uncomfortable because you feel hot—it’s uncomfortable because you feel freezing cold. You get goosebumps, you’re shivering, you’re piling on the covers.

Fever, also known as pyrexia, is defined as an elevation in body temperature above the normal range due to an increase in the body’s natural set point. Most people associate fever with infections, but fever can also frequently occur with autoimmune diseases, cancer, drug reactions, and even blood clots. Fever is not a direct result of these conditions, but rather a consequence of triggering the body’s inflammatory pathways. One key member of this inflammatory cascade is a group of molecules called pyrogens, which directly interact with the hypothalamus in the brain to produce fever.

The hypothalamus serves as the body’s thermostat. When triggered by pyrogens, the hypothalamus tells the body to generate heat by inducing shivering, goosebumps, and constriction of blood vessels near the surface of the skin. It even causes a subjective feeling of cold, which encourages behavioral responses to raise the body temperature, like reaching for the covers.

All of these things are adaptive when your body temperature falls below its usual set-point (about 98.6 degrees Fahrenheit), which typically occurs in cold weather. But they become abnormal in the setting of fever, when your hypothalamus signals to the body to raise its temperature well above the normal range.

If pyrogens suddenly disappear from the bloodstream, as is the case with intermittent fevers, the hypothalamus all of a sudden senses that things are way too hot, and tells the body to kick in its usual cooling-off mechanisms. That’s why people sweat profusely when their fever “breaks.”

This post originally appeared on Quora. Click here to view.

nextArticle.image_alt|e
iStock
arrow
travel
Why You Should Never Take Your Shoes Off On an Airplane
iStock
iStock

What should be worn during takeoff?

Tony Luna:

If you are a frequent flyer, you may often notice that some passengers like to kick off their shoes the moment they've settled down into their seats.

As an ex-flight attendant, I'm here to tell you that it is a dangerous thing to do. Why?

Besides stinking up the whole cabin, footwear is essential during an airplane emergency, even though it is not part of the flight safety information.

During an emergency, all sorts of debris and unpleasant ground surfaces will block your way toward the exit, as well as outside the aircraft. If your feet aren't properly covered, you'll have a hard time making your way to safety.

Imagine destroying your bare feet as you run down the aisle covered with broken glass, fires, and metal shards. Kind of like John McClane in Die Hard, but worse. Ouch!

Bruce Willis stars in 'Die Hard' (1988)
20th Century Fox Home Entertainment

A mere couple of seconds delay during an emergency evacuation can be a matter of life and death, especially in an enclosed environment. Not to mention the entire aircraft will likely be engulfed in panic and chaos.

So, the next time you go on a plane trip, please keep your shoes on during takeoff, even if it is uncomfortable.

You can slip on a pair of bathroom slippers if you really need to let your toes breathe. They're pretty useless in a real emergency evacuation, but at least they're better than going barefoot.

This post originally appeared on Quora. Click here to view.

nextArticle.image_alt|e
iStock
arrow
Big Questions
Where Should You Place the Apostrophe in President's Day?
iStock
iStock

Happy Presidents’ Day! Or is it President’s Day? Or Presidents Day? What you call the national holiday depends on where you are, who you’re honoring, and how you think we’re celebrating.

Saying "President’s Day" infers that the day belongs to a singular president, such as George Washington or Abraham Lincoln, whose birthdays are the basis for the holiday. On the other hand, referring to it as "Presidents’ Day" means that the day belongs to all of the presidents—that it’s their day collectively. Finally, calling the day "Presidents Day"—plural with no apostrophe—would indicate that we’re honoring all POTUSes past and present (yes, even Andrew Johnson), but that no one president actually owns the day.

You would think that in the nearly 140 years since "Washington’s Birthday" was declared a holiday in 1879, someone would have officially declared a way to spell the day. But in fact, even the White House itself hasn’t chosen a single variation for its style guide. They spelled it “President’s Day” here and “Presidents’ Day” here.


Wikimedia Commons // Public Domain

Maybe that indecision comes from the fact that Presidents Day isn’t even a federal holiday. The federal holiday is technically still called “Washington’s Birthday,” and states can choose to call it whatever they want. Some states, like Iowa, don’t officially acknowledge the day at all. And the location of the punctuation mark is a moot point when individual states choose to call it something else entirely, like “George Washington’s Birthday and Daisy Gatson Bates Day” in Arkansas, or “Birthdays of George Washington/Thomas Jefferson” in Alabama. (Alabama loves to split birthday celebrations, by the way; the third Monday in January celebrates both Martin Luther King, Jr., and Robert E. Lee.)

You can look to official grammar sources to declare the right way, but even they don’t agree. The AP Stylebook prefers “Presidents Day,” while Chicago Style uses “Presidents’ Day.”

The bottom line: There’s no rhyme or reason to any of it. Go with what feels right. And even then, if you’re in one of those states that has chosen to spell it “President’s Day”—Washington, for example—and you use one of the grammar book stylings instead, you’re still technically wrong.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios