(CNN) Today is World Refugee Day , and it comes as the world faces the worst refugee crisis in history . Here's what else you need to know to Get Up to Speed and Out the Door . (You can also get "5 Things You Need to Know Today" delivered to your inbox daily. Sign up here .)

1. Otto Warmbier

2. US politics

Donald Trump isn't on the ballot, but his presence looms large today as the most expensive House race in history ends. Parties and super PACS have spent more than $50 million in the special election in Georgia's 6th congressional district, in Atlanta's northern suburbs . It pits Democrat Jon Ossoff and Republican Karen Handel in a runoff that many see as a referendum on the popularity of the President . It may give us the first sign of whether Trump's sagging poll numbers could be a threat to the GOP's control of the House in the 2018 elections.

JUST WATCHED Democrats hope to turn Georgia's 6th blue Replay More Videos ... MUST WATCH Democrats hope to turn Georgia's 6th blue 05:26

3. Supreme Court

The high court will take up a Wisconsin gerrymandering case, the most important case of its kind in a decade. It involves district lines in Wisconsin that challengers say were drawn to help Republicans. How the Supremes rule on this one could impact how district lines are drawn nationwide

JUST WATCHED Does gerrymandering cause polarization? Replay More Videos ... MUST WATCH Does gerrymandering cause polarization? 03:34

4. Terror attacks

The suspect in the city's latest terror attack is Darren Osborne of Cardiff . Police say he was behind the wheel of the van that mowed down pedestrians near a mosque in north London. Osborne reportedly shouted, "I did my bit, you deserve it." Eleven people were injured, and one man, who was receiving first aid when the attack unfolded, was found dead at the scene.

JUST WATCHED How Muslims feel after the Finsbury Park attack Replay More Videos ... MUST WATCH How Muslims feel after the Finsbury Park attack 01:22

And that wasn't the day's only terror incident involving a vehicle in Europe. In Paris, along the famed Champs-Elysees, a car deliberately rammed into a police van . The driver, who was armed, was pulled out of the car by police before the car burst into flames. He later died; the car was packed with explosives.

5. Weather

The heat is on out West, where it's so hot that American Airlines has canceled about 50 flights in and out of Phoenix as the temperature there hit 118 degrees. Hotter air means planes need more speed (and more runway) to take off. Las Vegas may see its highest temperature ever recorded, while temperatures today in Phoenix (119 degrees) and Death Valley, California (127 degrees) will be scorching, as well. If that's not enough molten misery, wildfires are burning across California, which is also dealing with buckling roads and power outages caused by the increased use of air conditioners.

JUST WATCHED What NOT to do in a heat wave Replay More Videos ... MUST WATCH What NOT to do in a heat wave 01:14

BREAKFAST BROWSE

People are talking about these. Read up. Join in.

Lorde of the rings

She's a pop star and Grammy winner, but singer Lorde is running a tasty little gig on the side: onion rings reviewer.

Not alone?

NASA's Kepler telescope has discovered 219 more exoplanets , including 10 Earth-size worlds. Maybe, just maybe, we could actually live on one of 'em.

JUST WATCHED What is an exoplanet? Replay More Videos ... MUST WATCH What is an exoplanet? 01:18

Thermal thaw

It's raining in Antarctica , and if that sounds weird, well yeah, it is. Here's more weird: an area on the continent twice the size of California is melting. Not good.

Pint-sized perspectives

JUST WATCHED Director: 'Wonder Woman' a hero for all Replay More Videos ... MUST WATCH Director: 'Wonder Woman' a hero for all 02:41

Space sweepers

There are about 170 million pieces of space debris floating around our little planet. That's a lot of junk. Now a Japanese company has a plan to clean it up.

NUMBERS OF THE DAY

1,297

The number of children killed annually by guns from 2012 to 2014, a new study finds

200 million

registered US voters had their That's how manyhad their personal information accidentally leaked online by a GOP analytics firm

AND FINALLY ...

She will rock you