Humidifier help

I have been googling the difference between cool mist humidifiers and warm mist humidifiers all day and the only thing I can really find is that the cool mist ones are better because they wont hurt your baby. My baby is only 4 months old and he has a really bad cold and its his 2nd cold. Hes been congested pretty much since he was born and sneezes a lot. I was looking at the Vicks warm mist vaporizer humidifier. What one do you prefer and why? Whats better, warm or cool mist for congestion?