There are a few diseases that cause an insensitivity to pain. This question asks about the relationship between the cold and pain, which got me thinking:
Is shivering a response driven by the sensation of cold, or a response to the pain associated caused by the cold? This is easy to work out by considering people that do not experience pain.
The key here is if people with congenital analgesia (AKA CIPA, CIP) shiver then we may assume that it is the sensation of the cold, not the pain and the cold, that causes the shivering.
Do CIPA patients shiver in the cold?
Does this mean that the shivering is caused by sensation pathways or pain pathways?
Disclaimer: I am not an anatomist and do not claim to have a working knowledge of the nervous system. Please point out any and all obvious errors in this question that might explain why this wouldn't be the case in the comments or as an answer if its a big error.