The best way to treat chilblains is to not get them in the first place, ie prevention.
There are several strategies to do this. The first is obvious: do not let your feet get cold. Wear sufficiently warm thick woolen socks and closed in shoes to prevent the feet from becoming cold. Make sure you wear them whenever exposed to a colder environment.
If however, despite wearing all that protection, you are out in the cold and the feet do get cold, it is really crucial that the feet be allowed to warm up slowly. When coming back inside, do not put your feet right next to a heat source. That is a surefire way to get a chilblain. When a foot gets cold, the blood vessels close up to conserve heat. When a foot becomes warm, those blood vessels open up. What happens in a chilblain is that the blood vessels do not open up quick enough in the warmth and that sets up an inflammatory reaction. This means that when you get cold, the blood vessels need to be given time to open up in the warmth in order to prevent a chilblain, hence, do not put your feet next to a heat source immediately after it was cold.
If you do have a problem with chilblains and they are somewhat severe and the above approach does not seem to help then a drug, nifedipine may be trailed. This drugs keeps the blood vessels from closing up when you get cold, so they do not need to open up rapidly when you become warm.
If all this fails, then give thought to moving to a warmer climate to live!