Prime Day is heating up, but your bed does not have to. Amazon Prime Day has become one of the biggest moments of the year to upgrade sleep essentials at a discount — and cooling sheets are consistently among the most sought-after items. As temperatures rise and summer nights get stickier, many shoppers look for breathable bedding that helps regulate body heat without sacrificing comfort or softness. This year’s sales ( June 23 through June 26 ) are packed with options that promise cooler sleep