Metspitzer wrote:
What would make a good insulating material for a water bed?

My niece has a water bed. The heater from the water bed makes her
room hotter than the rest of the house. I suggested that she take a
blanket and put it under the fitted sheet and try to turn the heater
down a few degrees. She says that even with the blanket, if she turns
the heater down any the bed is too cold.

Try sheets of foam. You can probably get 4x8 sheets of 1/2" or 1/4" white
styrofoam at the hardware store or building supply store. Line the bottom and
sides with that, then use a thick comforter over the top (of her) to insulate
there. She's right, turning down the temp doesn't work. The bed just sucks the
heat out of you.