under mattress insulation

louiskathy wrote:

We found regular blankets can feel damp so we've switched to micro fiber/fleece blankets. I don't use regular cotton or even flannel anymore. Fitted sheets don't stay in place so we've just gone to the blankets being tucked under the mattress

I've found fleece sheets, fitted sets even, for our camper. Like you pointed out, they don't hold moisture like cotton or flannel. The fleece sheets are grippy too and the fitted sheet stays on the mattress quite well.
Fleece sheets are practically dry coming right out of the washing machine spin cycle. I can throw them on the bed and within a few minutes, they are dry enough to make the bed.

You can find them on Amazon.