Personally speaking as a southern Lousy-annian, I use a Falsa Blanket (cotton) sandwiched between two flat sheets and I'm good for 65deg F, on the boat, which is what our thermostats are set for. During winter, I have to add an additional blanket (no, we don't raise the thermostat during wintertime).

I use my sleeping bag as a mattress and cover with the falsa blanket during summer outings.

In wintertime, I crawl into the bag and use the falsa blanket on top as an extra layer of insulation.

The falsa blanket rolls up tight, fairly lightweight and breathes, unless sandwiched between two flats.

Thanks Susan for your info,,,now I know why, after all of those years of sleeping under cheap govt issued military blankets, why they were so scratchy. That is why I started sandwiching blankets between flats.