As a kid, I absolutely hated a warm pillow. I would have difficulty falling asleep because by the time I had rested enough to almost fall asleep, the heat of my pillow would annoy me and wake me up. I would either flip the pillow or sleep on the other end. In other words, the average pillow had four sectors. By the time I was done with all four, the original sector had probably cooled down to normal and I could switch to it. I remember being awake for at least an extra hour some nights because of this.
I no longer have this problem, otherwise I would run out and buy the Chillow! A small, flat but otherwise pillow-shaped insert, the Chillow acts as a heatsink and radiator. It makes one side cold and one side a bit warm. The warmth is absorbed by the pillow proper and dissipated leaving the surface nice and chilly. Hell, I might buy one anyway!