I used to not get severe burns but by the end of the night my tongue would just be a tiny bit "
" like i would eat certain things or drink cold water and i'd feel it even though it wasn't horrible, i finally moved to just filtered pipes and never had a problem again, at some point it wasn't worth it to me to worry about. I still have some unfiltered pipes but i smoke them less often and really dry the hell out whatever I'm going to smoke in them, also take smaller sips on them than the big pulls on my filtered pipes.