For some time now, my right arm has had this sensation of being burnt (for example with hot water or the sun) when I run my hand down it. It looks perfectly normal. I only notice it if I run my hand down it, normally it feels fine. It starts from about half way up the bone section before the joint (sorry, I don't know the names of the bones and what not), and seems to go all the way to my fingers. Any ideas what it could be?