Heavy rain flooded an Ohio highway where people were rescued from their cars, covered the Las Vegas Strip with water and temporarily closed a busy airport terminal outside Detroit.

Parts of the western United States have been deluged in recent weeks with rain from Tropical Storm Hilary, and much of the central U.S. was beaten down by deadly sweltering heat. In Hawaii and Washington, emergency crews battled catastrophic wildfires.

Authorities battling a major wildfire in northeastern Greece that has been described as the European Union's largest single recorded fire have recovered another body, the fire department said Friday, bringing the total death toll from wildfires in Greece this week to 21.

The fire department said firefighters recovered the body of a man from the Dadia forest national park, which lies near the border with Turkey, on Thursday.

The loss of ice in one region of Antarctica last year likely resulted in none of the emperor penguin chicks surviving in four colonies, researchers reported.

Emperor penguins hatch their eggs and raise their chicks on the ice that forms around the continent each Antarctic winter and melts in the summer months.

Major wildfires burning for days in northeastern Greece and on the fringes of the country's capital have incinerated more tracts of forest and forced additional evacuations Thursday as firefighters struggled against strong winds and arid conditions to bring the multiple fronts under control.

The wildfires have left 20 people dead over the last week. Eighteen of those, including two boys aged between 10 and 15, are believed to be migrants who crossed the nearby border with Turkey. Their bodies were found by firefighters near a shack in a burnt forest area in northeastern Greece.

Deadly heat that has gripped Texas for much of the summer has spread into other parts of the central U.S. this week where it is forecast to stay for days, with triple-digit temperatures buckling roads, straining water systems and threatening the power grid of the nation's energy capitol.

With heat warnings and advisories stretching from New Orleans to Minneapolis, the unyielding weather is stressing the systems put in place to keep resources moving and people safe. Just this week, a 1-year-old left in a hot van in Nebraska died, and Louisiana reported 25 heat-related deaths this summer — more than twice the average number in recent years.

Most octopuses lead solitary lives. So scientists were startled to find thousands of octopus huddled together, protecting their eggs at the bottom of the ocean off the central California coast.

Now researchers may have solved the mystery of why these pearl octopus congregate: Heat seeping up from the base of an extinct underwater volcano helps their eggs hatch faster.

The destructive power of wildfire has been a defining feature of a summer of climate extremes.

Dozens of people on multiple continents have died. Blazes have reduced homes and businesses to rubble. Thick smoke has darkened skies and carried fine-particle pollution thousands of miles from its source.

Rescuers have evacuated more than 100,000 people from flood-hit areas of Pakistan's eastern Punjab province in the past three weeks, officials said Wednesday.

The rescue operations were expanded last week when the Sutlej River started overflowing, inundating several districts. Most of the evacuations were reported in the districts of Bahawalpur and Kasur in Punjab province.

Water-dropping planes from several European countries joined hundreds of firefighters Wednesday battling wildfires raging for days across Greece that left 20 people dead, while major blazes also burned in Spain's Tenerife in the Canary Islands and in northwestern Turkey near the Greek border.

Greece's largest current forest fire was burning out of control for the fifth day near the city of Alexandroupolis in the country's northeast, while another major blaze on the northwestern fringe of Athens was burning homes and heading towards the Parnitha national park, one of the last green areas near the Greek capital.

A natural El Nino, human-caused climate change, a stubborn heat dome over the nation's midsection and other factors cooked up Tropical Storm Hilary's record-breaking slosh into California and Nevada, scientists figure.

Cooked up is the key phrase, since hot water and hot air were crucial in rapidly growing Hilary and then steering the storm on an unusual path that dumped 10 months of rain in a single weekend in normally bone-dry places. Nearly a foot of rain fell in parts of Southern California's mountains, while cities smashed summertime records.