Love the width of this pillow. As as side sleeper, I find that my head is at the perfect angle for sleeping. I can't say, though, that I notice a special "coolness" about it. I tried my old pillow and then the new one and noticed no difference in temperature (though the comfort of the new one far exceeds my old memory foam one). Perhaps this is because I have a pillow case on it? Is the idea to sleep on the thin cover it comes in? My pillow case is linen, so I expected the coolness of the pillow to work well with the natural coolness of the linen. All in all, I am happy with my purchase, but I thought I was paying quite a bit more than I usually would for a pillow because it would be keeping my head cool at night and, in that sense, it is a bit disappointing.