The bed pad (or half-sheet) is intended to be used across the width of the bed. Over your bottom sheet, so that the bare skin of your feet come in contact with the sheet. All you have to do it tuck in the ends under the mattress. Rather than create a lot of different lengths to fit different size beds, it was decided to just create one or two. From your side, all you need to do is tuck in the extra length under the mattress. Martin Zucker, co-author of the Earthing book.