The other day we had a small discussion involving this mather. The operator asked me if I wanted something to drink. So, with it being a hot summer and all I asked for a cool can of coke. The operator claimed that fizzy drinks in the chamber, under pressure, are no good. He didn't really knew why but for keeping it on the safe side, he offered me cold water. So now, opinions are a bit divided amoungst the team. Some say don't others say do! if you don't mind burpin' and fartin' more. So does anyone know?