Hi Rachel...I have SFN which was diagnosed with a biopsy of my epidermis. My toes burn and the sides of my feet where the sole meets the top of the food. It is a sensitivity to heat...i.e. not from within. So for the cause is idiopathic. l As long as I am in A/C or have a fan blowing over the feet they do not burn. I have some numbness in my hands and lower legs. I am not taking any pain meds, only topicals like Sarna lotion that is for itching and sunburn. I have a bit of cramping in my arches and calves but so far not debilitating. I swim and hike my nearby mountains everyday still. I was only diagnosed two weeks ago after months of misdiagnoses my several doctors. I do have a high tolerance for pain as I am on a mission to do as much good in the world as I can...I may be time limited now and I have to keep going somehow...I also worked 29 years as an engineer solving some "wicked" problems so this problem qualifies as "wicked" and I intend to get to the bottom of it. I am also writing a book and need to finish it...lots of challenges ahead...This forum has been the invaluable to me. Pam