Another use for socks with holes in the heels is if you have a white dressing on your hand or wrist, to keep it them clean. Cut off the feet just above the hole and just use the top, For the wrist pull them on with the elasticated part nearer the hand, For the hand, cut a slit first for the thumb, and wear them like a fingerless mitten, with the elastic at the base of your fingers. The longer the top, the further it stretches up your arm and tucks under the sleeve of a shirt or jumper. They can be washed and re-used, or thrown out when they get too dirty and/or ragged.
If the foot part is OK, you can also pull that over the fingers to keep the hand warm when a glove won't cover the dressing - (the thumb is still out in the cold, but you can tuck it inside the top.).