My hands and feet are always burning up. even in the winter. it is so hot that i can't even sleep. what can cause this?

Acrodynia: The best sense i can make out of the symptoms you report is a rare condition called "acrodynia" (which means painful hands & feet). This is usually due to heavy metal poisoning like from mercury, etc. Otherwise you may have a painful peripheral neuropathy, which can be due to something like a cyst in the spinal cord or from unknown causes. Best to see a doctor to clarify.

Neuropathy: Can cause burning. You need to be evaluated by your family dr.