The submitter was out with some friends for dinner when this was suddenly uttered. An instant malaphor alert went off. This is a nice, alliterative congruent conflation (best kind of malaphor, imho) of “send shivers up (one’s) spine” and “makes (one’s) skin crawl”, both meaning to cause to feel frightened or unnerved. Spine and skin are mixed here, and the visual of shivers crawling. Certainly your skin shivers when you’re cold, so the mixup is quite expected. A big thank you to Steve Grieme for hearing this one and passing it on!