They’re not EXACTLY hand warmers, though you might be able to make a case that they are pretty damned close, but with a different name. We supposed that they might have needed a slightly warmer version in Scotland. It is August right now, and VERY chilly.
http://www.metmuseum.org/collection/the-collection-online/search/156922
And for those of you looking for a pattern, these are lovely (bottom of page) :
A Dram of Outlander 