I don't know what you consider to be a warmer climate, but I'm in the midwest US and it goes from around -10°F to 110°F here throughout the year. The temperature outside has pretty much nothing to do with my choice of bedding though, because it's always within 1° of 67°F inside my home unless my HVAC system is broken.

I know a lot of places aren't as into complete climate control as we are around here, so it makes sense that those places would have different priorities when making bedding choices, now that I think about it. Thanks for sharing.