My first thought would be that maybe it has to do with blood pooling in your limbs. I don't get shivers but I do feel sort of,, cold internally when I get pooling. Not sure if this is what you're dealing with but it could help to elevate your legs or try to get your blood flowing a bit if you can 😊

Sorry I don't have any answers for you Javen. Just here to say, yeah me too. I am also looking for answers. You are not alone. How long has this been happening for you and how frequently out of interest?

Me too. Hot and cold both, no rhyme or reason on which extreme. I always wear layers. Long sleeve shirts easy to push up sleeves, button up top shirt to open/,close as needed, very light compression socks (i buy a size larger, often just ankle height ones), i almost always have legs up and reclining position or with legs tucked under like kneeling. Raynauds syndrome is common