I can't say that 54 degrees--if dressed properly--would feel quite that cold to me. I do know that I need to maintain a pretty good clip when it's cold; otherwise I don't work up enough body heat to stay warm. Have you ever talked to a doc about whether you have a circulation problem or some other issue that might make it hard for you to stay warm? I hate to keep beating this particular drum, but hypothyroidism can make you cold intolerant. Yet another reason to make sure you're taking your meds.