Fridge not cold. My Fridge is not getting cold but the freezer is working great. It is one that my

Question

My Fridge is not getting cold but the freezer is working great. It is one that my girlfriends dad has been using for quite some time & it worked well. When I got it here it worked great at first. When this started he said something about having to take a hair dryer to a hole in the back of the freezer? Help, my food is gonna waste quickly like this.