My daughter is 8 weeks old. her head feels cool tonight and i'm wondering if it is something i need to be worried about. she had a cold a few days ago?

Take her temp: Newborn's blood flow to their skin and extremities is extremely variable. That's why they often have cold hands/feet, and can one moment feel hot and next cool. The way to figure out if she is really cold is to take her temperature. A rectal temperature is the most reliable in a newborn or small infant, unless you have invested lots of money in good ear thermometer. If temp is fine, she's fine.

Cool head: I really would not worry about a colder head if there are no other symptoms to go along with it. No chills ? Just watch her tonight and she will be fine. Good luck! good health!