With the Extreme Q, I use 200 C. Less than that and it won't fully vaporize fast enough to breakthrough or get a full bag of vapor. Higher than that and it starts to get harsh. Note - I don't let it heat up at all, just start at lowest fan setting then increase to the middle one once I see thick vapor in the bag. This has been the best compromise between complete vaporization and smooth vapor for me in the past. I'm thinking of trying 195 some time.