I'm not sure where you live, but I'm in the south where we barely ever get cold weather. I give both of my kids a bath at night and usually will towel dry their hair, but not dry it completely and they have been fine. They have gotten colds, but even the dr has said that putting them to bed with wet/damp hair is not the reason. He told me that as long as they are inside and it is warm, they should be fine. Teething can be one reason, but allergies would be a good reason too. Does she have any allergies that you know of? My youngest has major allergies and the dr did tell me that what might seem like a cold could just be a bad allergy reaction (sneezing, coughing, etc like a cold) to something (such as pets, mold, dust, etc) in the house. My daughter started having allergy problems at 6 wks and she was put on an allergy med then. She is now 2 and I give her allegra and then at night if she seems to need something, I give her children's benedryl.