I do a lot of fitness walking in all seasons, and I find that cotton socks tend to give me more blisters than wool socks. I particularly like SmartWool thin merino wool athletic socks for walking in 'regular' weather or even hot weather. When it's cold I wear thicker wool socks- I like the SmartWool cushioned hiking socks for colder walking.
Make sure your socks fit you and are not too loose or they will move around too much and rub your skin. It's also possible that your 'walking boots' are not good for long distance walking.
In the meantime, do put bandages or a patch over those blisters.