Why do you keep warmer wearing several layers of clothes, rather than one thick layer? How will putting insulation in my loft save me money? Why does the ice not melt, even though the water is boiling at the top? Water Ice cube Why do birds fluff up their feathers when it is cold? Why are metal saucepans better than glass ones? If I use cork table mats my dinner stays hot for longer – why? How does my quilt keep me warm? Why are frying pan handles made from plastic, and not metal? Why is frozen food transported in polystyrene boxes?