Hi John - 6 years ago they did an EMG and saw Severe Axonal Sensorimotor Peripheral Neuropathy, then did the standard checklist of autoimmune and cancer bloodwork and found nothing, do the label Idiopathic was added. I have never had an MRI or skin biopsy, as it’s believed they wouldn’t add any useful information on diagnosis or treatment. The Gabapentin prescription is pretty much the only assistance I get from Neurologist, though sometimes they check my basic arm and length strength, and see if I still don’t have knee/elbow reflexes. The Gabapentin I take comes in a 800mg tablet, and I try to keep them 8 hrs apart. I’m lucky that pain, when it comes, it isn’t a 10, it’s can get to 5 or 6, just enough to know it’s not comfortable and you can’t take your mind off if it, so the medicine can make you maintain at a 0 to 2 all day every day if I’m on a good spell. But if my fingers/toes get cold, that’s the worst type of pain a heating bag and gloves couldn’t cure - the iciness was bone deep, so helpless. That’s the biggest help from Gabapentin for me; it has made those episodes much less frequent and more tolerable when I get a little. Heat like you’re experiencing also happened with me, but to a lesser extent. I can’t avoid the outside temperatures, and I guess it’s because I don’t sweat that makes it tough for me, but it was worse before Gapapentin.