LizaJane could have hit the nail on the head. Here's a link to the hypothyroidism article put out by the Mayo Clinic:
http://www.mayoclinic.com/health/hypothyroidism/DS00353 .
The cartoon I saw had old people in it, but my meaning was for people who feel cold when everybody around them feels comfortable or warm. No offense was meant, not that I think there's anything ofensive about being "old". Being "old" certainly beats being dead, or being as socially insecure and unhappy as many young people are. At 64 I'm getting there myself. I put "old" in quotes because I don't know that "old" is a good description. I remember being in kindergarten and thinking that there was no difference between the 6th graders and the teachers. Both groups were big people and both were old people.
A recent study found that people get happier and more content the older they are, even into the 90's as long as they are reaonably healthy. If not, it's the health that's an issue, not their age. You and I are both pretty sick right now. I think we'll both be very happy to get our health back and go back to our fun, satisfying, and often joyous lives.
When do you go to Mayo?