Is the ice in the freezer edible?

How do doctors name phobias? Is the ice on the freezer sides safe to eat? What is the low-frequency hum I can hear? Is pipe tobacco tar good for cuts and sores? Why do birthmarks persist? What keeps the head so hot? Why are animals alarmed by loud noises? A bumper crop of science questions awaits Dr Chris in this week's Ask the Naked Scientists... Like this podcast? Please help us by supporting the Naked Scientists Like this podcast? Please help us by supporting the Naked Scientists