What Causes Tingling Of Lips And Fingertips In Hot Shower Or Hot Food?

I am an almost 35 year old female, weighing about 130 lbs. When getting into a hot vehicle, taking a hot shower, or sometimes eating hot foods, I sometimes get a tingling sensation in my lips and fingertips. I am a diabetic of 28 years, but it doesn't seem related to blood sugar. There is no pain at all, and it usually subsides fairly quickly. I had surgery on my neck about 5 years ago and didn't know if it could be related to nerves. Any thoughts on a possible cause?