one scenario I'll do that. When I'am drinking or something similar with friends who smoke cigs. So when they step out for a smoke I'll take the pipe and get a few 20 minute sessions in. Mainly cause in those scenarios people will smoke two or three cigs. Otherwise I'll not do that. If I have to stop a bowl I'd rather dump it and start over. Oh or if I am running out to a shop and get there in the middle of the pipe. I'll let it go out and then light it for the return trip. Though one time I did forget and left the pipe in while shopping. No one seemed to notice either.