It is mildly embarrassing but seems to be common enough. It can happen too easily when you are outdoors in the cold - I always end up puffing too fast in the winter because it's freezing outside; next thing you know, the bowl starts to get hot and you're tongue bitten. Then you lay off and take little sips, after awhile those billows you're expelling are nothing but steam if you aren't watching it - I usually call it quits and dump the dottle, at that point!