I'm with you, but I do hike in cold temps also. My latest pillow I made, it is silk on the outside and polyfill on the inside. I haven't got to use it in high temps yet, but it seems to help regulate the temp around my head a little more than a standard blow up pillow or other backpacking pillows. I made a bigger version of it to try, but it's to big for my taste, if you want, just pay shipping and I'll send it your way, and you can try it out. It is similar to this one but it is blue and white. The pillow in this thread is silk on one side and ripstop on the other, the one I'll send you is silk on both sides. Let me know if you want to give it a try.