that is what people say but some say it's just a plain ole steam burn (which goes deeper than other burns). No matter what it's a rite of passage for pipers (just annoying Mr. Embers).To my understanding - please correct me if I'm wrong - the bite is due to a chemical burn (smoke and ash are alkaline, some kind of tobaccos can create a more alkaline smoke than others).
The faster you smoke, the more smoke you create and keep in your mouth, the more you concentrate this alkaline PH in your tongue to a level that it cannot be washed out by your saliva and the feeling is like a burn.