What Causes Blister Along With Numbness On Big Toe?

I have a blister on my big toe from frost bite and numb on the end of the toe. It first started out as a dark blue tip. my girlfriend rubbed it and got the circulation going. the next day it was redish purple. Now it is skin tone pink with a watery blister on it. The area that has the blister is tingly numb. What should I do?
Sincerely Ron