What You Should Try: Specialists usually give a ballpark suggestion of setting the thermostat to between 65 and 72 degrees—or that it feels just chilly enough so that you need a blanket. However, some cotton-blend sheets and pillowcases trap heat, as do memory foam mattresses. So you may doze off feeling snug, then wake up hot three hours later.
Keep Cool: There's an expanding range of products that claim to regulate your temperature while you sleep, including a brand-new line of cooling apparel from the bedding company Sheex. You could also set your air conditioner's timer to drop a few degrees in the middle of the night, or sleep with a fan.