Whether it’s for a overworked muscle or to heat up the sheets in the winter, these Reusable Heat Pads are fantastic! I have several of them and use them regularly for headaches, backaches and yes, to warm the sheets in the winter. Now I know why they used bed warmers in medieval times! Member Lizzle put together a super simple tutorial for the heat pads and you can whip them up in no time at all.