My first one was cold. After a bit, I noticed some mold (I was NOT doing the proper cleaning at that time). When I went to look for a new one, I saw that the warm was cheaper and my son had been sick at the time, which seemed to be recommending the warm. This required a lot of maintenance (don't know compared to the cold since I never read that), and I was worried about it as my son got more active. The air does come out pretty hot, and I had more of a fire danger in my mind. Plus, there seemed to be more issues if it ran out of water than with the cool one. If I had to do it again, I think I would have bought the cool one again, as we rarely, if ever, use the warm one now.