Wet hair, cold head? Wear a hat to bed!
My daughter took a bath before bed and was uncomfortable and cold because her hair was wet. Being that this time of year the heat doesn't always kick in as much as during the winter, some days it just "doesn't feel warm" in the house. So, we decided to let her wear a winter hat to bed. Her head was nice and warm and the complaints stopped :) Yes she did have one major case of hat head in the morning, but we just spritzed and combed out and we were good to head out the door.
My kids also bathe before bed and I've found that thoroughly towel-drying their hair makes a big difference. I'm a fan of the Turbie Twist hair drying towel because it's not bulky and stays put, but any thin towel would do well, including your old, hooded baby towels.
Related: How to make a hooded towel for kids