Cooling
Winner: Purple HarmonyThe Purple Harmony's GelFlex Grid runs notably cooler than Coop's shredded memory foam — the grid pattern vents heat that any solid or shredded foam can't. We haven't measured a temperature difference between the two pillows and won't quote one.
Coop uses a breathable knit cover which helps but doesn't match the grid's ventilation. If you sleep hot and pillows are part of the problem, Purple is the clear pick.

