I said in my above post 70 degree's, I should have said 70% (percent) which is the measure for humidity, ( not degree's ) Sorry for my error. I remembered that this morning when I woke up and I was looking at my snakes humidity. But no it won't matter whether it is cool mist or vapor mist. But I think (IMO) for the kids sake and for better humidity, warm mist and vicks vapor rub on the chest, works better for the humidity and their colds. IMO only.