I relate about the thyroid. One of my childhood memories was me clinging to a huge gas heater and hugging it to get warm. Later "my spot" in the house was on the floor on the heat vent.
it's ridiculous. I was always sensitive to cold, never really gave it any thought. I just assumed it was because we moved to the south when Iwas little so I just didn't have time to get used to cold. What I think is the most ridiculous is that mine is only slightly slow. Like, I take the smallest dose of synthroid but I'm amazed at how much havoc it causes at such a slight level. It's crazy. I have no idea how folks like my bff deal. She had her thyroid removed in HS.