Some customers claim that down pillows sleep hot, and they may not be too far from the truth. In fact, the inclusion of down filling, more so that with a ratio of feathers, makes the sleeping environment a little warmer than those pillow types without such fillings. Many believe that feathers encourage the heat to circulate around them and therefore this heat is increased as you lay upon your pillow. This may be more of a personal note, but it’s also a good idea to opt for pure down instead of one with a ratio of feathers if you tend to sleep hot in general.