Chilblains, prevention is better than cure with chilblains. This condition is caused by the micro-circulation/capillaries being starved of blood supply due to too rapid heating of the foot from cold. Other conditions such as Raynaulds predisposes people to this condition. Therefore keeping the feet at as constant a temperature as possible and not applying direct heat when they are cold, will help prevent their formation.
If chilblains do develop, most chemists will stock over the counter creams such as Balmosa etc. (these are only useful if the skin is not broken). Chilblains will eventually heal on their own if the cause is avoided as above.