text:  This is Morning Edition from NPR News. I'm A. Martinez. And I'm Michelle Martin. It's been a scorching summer, and that means air conditioners are working overtime. But not everybody can afford to stay cool. NPR's Scott Horsley has a report on new research that shows how some families sacrifice comfort and even safety to keep their electric bills in check. The temperature in West Point, Mississippi, has been close to 100 degrees this past week, and the humidity has been just as high.