Mine has Low, 2, 3, 4, 5, and High. So I guess 3 and 4 would be Medium. My setup is in my laundry room which is a relatively warm room as it has a heat vent in there and no outside doors or windows so the room stays fairly warm. I will leave it on 3 for now and then check it in the morning and just use my judgement I guess. Is there such thing as "too hot" for dubias??