Six times as much snow must be eaten to provide an equal amount of water. Furthermore, calories are used to melt the snow that should be used for body warmth. A heavy winter hair coat is a horse's first defense from the cold. When allowed to grow, a horse's natural hair coat acts as a tremendous insulator and provides as much warmth as the best blankets. Horses that are to be maintained outside should be allowed to grow a long hair coat, plus the hair within the ears and around the fetlocks should not be clipped throughout the winter months.
Cold weather causes the hair to stand up, trapping and retaining body heat.
Once the hair coat becomes wet, the hair lies down and loses its insulating ability. A long fuzzy hair coat can be deceiving of a horse's true body condition. The most accurate assessment of body condition is done through feeling the condition over the horse's ribs, plus visual inspection of overall condition. Although stalling is not necessary for all horses, some protection from the winter elements is desirable. Horses acclimate to winter conditions extremely well but need to be able to escape the bitter winds and moisture.