The Weather Channel's Alex Wilson looks at the history of wind chill.

Wind chill is a measure of how cold it feels to humans when wind combines with low air temperatures. The concept originated during World War Two, when researchers in Antarctica studied how quickly water bottles cooled in the wind. While the human body doesn't lose heat exactly like a water bottle, the principle is similar: wind removes the protective layer of warm air around the body, making it feel colder than the actual air temperature.

The National Weather Service updated the wind chill equation in 2001 to better reflect how cold it feels to people. The wind chill factor is not meant for animals or objects, but rather gives an estimate of the risk of frostbite and discomfort for humans. Factors such as physical fitness and activity level can also influence how cold someone feels. Experts recommend dressing in layers and staying indoors during extreme cold to stay safe.

Just what is wind chill?

buffaloes and penguins. They just don't seem to mind. But we humans are keenly sensitive to one of weather's most miserable miseries. The windchill factor. This is crazy weather about the worst I've been in. This is your basic blizzard. We're right off Lake Michigan. Winds are gusting over 45 miles an hour. It's six degrees. The windchill is 14 below. What exactly is windchill and how did meteorologists know it was 14 degrees below zero? The windchill concept was born during World War Two in the frigid Antarctic when researchers Paul Seipel and Charles Purcell measured cooling rates of water bottles hung near weather instruments. People don't lose heat exactly like water bottles, but it's a similar process. The human body radiates heat, forming a protective layer of warm air. But cold winds literally blow away that warm layer, so you feel colder even at the same air temperature. As the understanding of the human body improved, so did windchill science. In 2001, the National Weather Service adopted this updated but brain freezing equation to better calculate windchill feels like temperatures for humans. But all you need to know is the lower the air temperature and the higher the wind speed, the colder you will feel and the sooner you could get frostbite. The windchill temperature equation isn't for animals or water bottles. It's a mathematically derived number that approximates how cold your skin feels. Physical fitness, activity and different body types also factor in. Still, the windchill factor is a good indicator of outside winter misery and even danger. So layer up, cover up and during the coldest weather, stay inside and stay safe.

Amazon.com cloud service returned to normal operations on Monday (October 20) afternoon, the company said, after an internet outage that caused global turmoil among thousands of sites.

Amazon says AWS cloud service back to normal after outage

Japan's parliament has elected the country's first female leader. Sanae Takaichi, 64, of the ruling Liberal Democratic Party (LDP), is seen as a hardline conservative who supports traditional gender roles and hawkish foreign policy.

Tokyo

Sanae Takaichi elected Japan's first female prime minister

Three days after meeting Ukrainian President Volodymyr Zelenskyy at the White House, U.S. President Donald Trump said Ukraine “could still win” its war with Russia, but added, “I don’t think they will,” raising new questions about Washington’s support for Kyiv.

Washington

Trump doubts Ukraine will win war against Russia

Former FBI Director James Comey is asking a judge to dismiss the criminal charges against him, claiming the prosecution is vindictive and unlawful.

Ex-FBI director James Comey seeks to toss indictment

An appeals court panel is allowing the White House to federalize and deploy National Guard troops to Portland, Oregon.

Portland

Appeals court rules Trump can deploy National Guard to Portland

U.S. President Donald Trump and Australian Prime Minister Anthony Albanese signed a rare earths and critical minerals agreement aimed at ensuring a steady supply of the materials at a time when China is trying to tighten control over global supply.

Washington County

U.S. and Australia boost rare earths supply with new agreement

A global outage hit Amazon Web Services (AWS), disrupting platforms like Amazon Prime, Fortnite, Alexa, Snapchat, and Duolingo. The issue, caused by increased error rates, took about three hours to mostly resolve.

AWS outage mostly resolved after hours-long global disruption

Centrist Rodrigo Paz won Bolivia's presidential runoff, defeating conservative rival Jorge "Tuto" Quiroga, as the country's worst economic crisis in a generation helped propel the end of nearly two decades of leftist rule.

La Paz

Centrist Rodrigo Paz wins Bolivian presidency

After 10 years in prison without charge, a Lebanese judge has ordered the release of Hannibal Gadhafi, son of the late Libyan leader, Moammar Gadhafi. But it’s on condition that he pays $11 million bail, something his lawyers say they will contest.

Beirut

Lebanon orders Hannibal Gadhafi’s release after 10 years

A cargo aircraft skidded off a Hong Kong runway and collided with a security patrol car before both fell into the sea early Monday, killing the two people in the car, authorities said.

Kowloon

Two killed after cargo plane veers off runway in Hong Kong

Thieves wielding power tools have struck at the famed Louvre Museum in Paris, stealing priceless jewels in a brazen heist that took just four minutes, according to the government. The thieves struck after the museum had already opened its doors to the public, with a major investigation now underway.

Paris

‘Priceless’ jewels stolen from France’s Louvre Museum in four-minute heist

U.S. President Donald Trump says he is ending aid to Colombia after the country’s president, Gustavo Petro, accused the U.S. of ‘murder’ when it struck a small boat within Colombian territorial waters in September.

Bogotá

Trump ending aid to Colombia after 'murder' accusation

The Israel-Hamas ceasefire is under pressure, as the Israeli military carries out strikes on southern Gaza and accuses Hamas of opening fire on its forces. Meanwhile, Israel alleges Hamas is stalling on returning the remains of deceased hostages.

Tel Aviv-Yafo

Middle East Conflict

Israel, Hamas clash in major test of U.S.-backed ceasefire

The National Guard could soon be on Chicago’s streets after US President Donald Trump took his case to the country’s highest court - the conservative-leaning Supreme Court.  The President says the city is a war zone - and is in the midst of a rebellion, as residents protest his migrant deportation policy.

Chicago

Supreme Court to decide on sending the National Guard to Chicago

China's second-highest ranking general and eight other senior officials have been expelled from the ruling Communist Party and the military on suspicion of serious misconduct linked to corruption.

Beijing

China expels nine senior officials from Communist Party

The United States is sending the two survivors of a Thursday (October 18) strike in the Caribbean to their home countries of Colombia and Ecuador to be detained and prosecuted, U.S. President Donald Trump said on Saturday.

U.S. will repatriate survivors of Caribbean strike, Trump says

The two sides have agreed to hold follow-up talks in Qatar to establish conditions and a framework for lasting peace, bringing an end to a week of deadly cross border skirmishes, which have killed dozens of people.

Doha

Afghanistan, Pakistan agree to immediate ceasefire, Qatar says

France's world-famous Louvre museum in Paris was forced to close on Sunday after thieves broke into Apollo Gallery and stole valuable crown jewels.

Jewels of 'inestimable' value stolen from Louvre in major heist

U.S. President Donald Trump's critics took to the streets Saturday, with millions nationwide participating in "No Kings" rallies, protesting Trump's demonstrations of power.

Anti-Trump "No Kings" protests held across U.S.

The Trump administration is awaiting word from the Supreme Court after asking it to allow the immediate deployment of National Guard troops to Illinois to protect Immigration and Customs Enforcement officers. A lower court blocked the move.

Tensions rising in Portland, Oregon over immigration tactics

President Trump posted a video of a U.S. military strike on a submersible suspected of smuggling drugs. Two people were killed in the strike but the survivors were brought to a Navy ship. Trump says the U.S. will send the them back to their home countries for prosecution.

Trump says survivors of U.S. drug submersible will be sent home

The U.S. State Department issued a warning that Hamas appeared to be planning an attack 'against Palestinian civilians,' warning that such an attack would 'constitute a direct and grave violation of the ceasefire agreement'.

State Dept. flags ceasefire violation by Hamas

Britain's Prince Andrew said on Friday he would give up using his title of Duke of York following years of criticism about his behavior and connections to the late U.S. sex offender Jeffrey Epstein.

Windsor

Prince Andrew gives up title of Duke of York

Ukrainian President Volodymyr Zelenskiy came to the White House on Friday looking for weapons to keep fighting his country's war with Russia, but met an American president who appears more intent on brokering a peace deal than upgrading Kyiv’s arsenal.

Ukraine Invasion

Trump pauses on sending Tomahawks to Ukraine

Tension is rising between the U.S and Venezuela. The latest threats from the US warning of stronger measures against Nicolas Maduro’s government — have sparked both fear and fragile hope across Venezuela.

Caracas

Venezuela on high-alert amid U.S strikes

In the aftermath of a destructive Typhoon Halong, historic floodwaters have destroyed remote communities across western Alaska, forcing hundreds of evacuations that could continue for days.

Kipnuk

Mass evacuations in Alaska after record floodwaters

Mr. Trump seemed open to trading U.S.-made Tomahawk's for Ukrainian-made drones, but then he argued Ukraine might not even need new weapons if he can broker a swift end to the invasion.

Trump says he'd rather broker peace than send Tomahawks to Ukraine

President Trump announced that he has commuted former New York Rep. George Santos' sentence on Friday in a post on his social media platform Truth Social.

President Trump commutes George Santos' sentence

The head of the World Trade Organization said on Thursday (October 16) she is urging the U.S. and China to de-escalate trade tensions, warning that a decoupling between the world's two largest economies could reduce global economic output by 7% over the longer-term.

WTO urges U.S., China to ease trade war or risk global growth

John Bolton pleaded not guilty at a Maryland federal court on Friday (October 17). This comes after the former Trump administration national security adviser was indicted on 18 counts for his alleged mishandling of classified information.

Breakdown