GEOFF BENNETT: Welcome to the "NewsHour."

Relief has finally arrived for regions of the country that have been boiling under intense heat.

A cold front helped today to lower temperatures across much of the Upper Midwest, the Northeast and the mid-Atlantic.

AMNA NAWAZ: Temperatures are also easing slightly across the Southwest after Phoenix endured 31 straight days of highs above 110 degrees.

But, in California, the heat is still fueling wildfires.

Crews today battled the fire burning out of control in the Mojave National Preserve.

The property manager at former President Trump's Mar-a-Lago estate made his first court appearance today in a classified documents case.

Carlos De Oliveira faces charges that he hid security footage at Mr. Trump's direction and lied to investigators.

De Oliveira left the hearing in Miami without entering a plea because he hasn't found a local attorney yet.

He's now free on $100,000 bond.

Hunter Biden's former business partner says then-Vice President Joe Biden spoke with their associates, but never about business.

Devon Archer was interviewed today by the House Oversight Committee.

Afterward, Democrat Dan Goldman said Archer testified that Hunter Biden sold the illusion of access to his father.

Republican Andy Biggs said the testimony justifies an impeachment inquiry.

In Pakistan, the Islamic State group has claimed responsibility for Sunday's suicide bombing that killed 54 people, including five children, and wounded 200.

It happened at a pro-Taliban election rally in the northwest near the Afghan border.

Tents were still in tatters today and upturned chairs littered the ground.

Hospitals were overwhelmed and victims' relatives clamored for answers.

ABDUL HAMEED, Pakistani Shopkeeper (through translator): I am a shopkeeper.

And I was also present at the rally with my son, who got injured.

We lost loved ones, so many martyred in the incident.

I demanded the government investigate this because this was a brutal act.

Now we don't know what will happen in the future.

AMNA NAWAZ: The ISIS claim of responsibility gave no details.

Instead, it said it's waging war on democracy as -- quote -- "a regime hostile to true Islam."

A new attempt at a cease-fire is under way in Lebanon tonight, after three days of clashes between rival Palestinian factions at a refugee camp.

At least nine people have died.

Earlier today, plumes of smoke dotted the skyline in the southern port city of Sidon, as Fatah loyalists battled Islamist groups.

Palestinian refugees took shelter wherever they could.

EM KHALID, Palestinian Refugee (through translator): We fled because of the shelling and the bullets.

It was falling on us.

Too many people were killed.

We cannot stay and have ourselves and our children die.

We cannot stay.

And we do not want those armed fighters here.

AMNA NAWAZ: The violence erupted Saturday after a gunman tried to kill a Palestinian militant.

Islamist fighters struck back Sunday, killing a Fatah military commander.

Russian missiles killed six people and wounded 75 today in Central Ukraine.

The attack targeted the city of Kryvyi Rih.

It's President Volodymyr Zelenskyy's hometown and far from the front lines of the war.

Rescue crews searched for survivors in the rubble of an apartment complex and a university building.

Officials say a 10-year-old girl was among those killed.

A group of 15 West African nations is imposing sanctions on Niger after the military coup there.

It's also threatening military force if the country's elected president is not reinstated.

At the same time, the president of neighboring Chad, Mahamat Idriss Deby, arrived in Niger on Sunday.

He's meeting with both sides to try to mediate a solution.

Back in this country, Wall Street started the week with a modest advance.

The Dow Jones industrial average gained 100 points to close at 35559.

The Nasdaq rose 29 points.

The S&P 500 added six and is now at a 16-month high.

And actor and comedian Paul Reubens, known by millions as Pee-wee Herman, died Sunday night after a long struggle with cancer.

Reubens hit it big in the 1980s with his Emmy-winning Saturday morning TV show "Pee-wee's Playhouse" and with two movies.

After that, a 1991 arrest for indecent exposure put his career on hold for years.

Paul Reubens was 70 years old.

Still to come on the "NewsHour": country music star Jason Aldean defends his new hit song that's been criticized as racist; whistle-blower testimony reignites the debate over UFOs and the possibility of alien life; American swimmer Katie Ledecky makes history again with major wins at the world championships; plus much more.