LISA DESJARDINS: In tonight's other news, at least six people are in critical condition after a knife attack inside a Michigan Walmart.

Authorities say this was a random attack, that a 42-year-old man walked into the store Saturday night and used a folding knife to attack a dozen people.

Customers helped a sheriff's deputy subdue the assailant and treat others who were attacked.

The suspect is in custody now.

Prosecutors look to charge him with terrorism and assault.

Overseas, there is hope for resolution in the conflict between Thailand and Cambodia.

The leaders of both countries have agreed to meet in Malaysia tomorrow for cease fire talks.

The clashes stem from disputes over a 500 mile frontier between the two countries and dozens have been killed and more than 200,000 displaced.

President Trump threatened to cut the nations out of trade negotiations if they don't reach an agreement and end the conflict.

And millions of Americans are under an extreme heat risk as we start a new week.

The National Weather Service warns a long lasting heat wave will intensify across the Southeast and Tennessee Valley.

While temperatures will soar, it's the humidity that will lead to feels like temperatures in the triple digits.

But relief is on the way.

Meteorologists predict a cool front will make its way through much of the country and lower temperatures as soon as Friday.

Still to come on PBS News weekend, we explore new cases of people posing as ICE agents and carrying out crimes, how funding cuts to national parks may harm the communities that surround them.