Millions of people in the U.S. are trying to stay cool as the summer's first major heat wave continues to create dangerous conditions across the Midwest and along the East Coast. That heat is expected ...

U.S. sales of heat pumps overtook sales of gas furnaces last year. But what exactly is a heat pump, and why do some call it a key climate solution? Julia Simon of NPR's Climate Desk has this report.

Heat pumps are essential for ditching fossil fuels. The appliances are many times more efficient than even the best gas furnaces, and they run on electricity, so they can draw power from renewables ...