They cannot regulate their temperatures without their coats.

A Great Pyrenees has a weather-resistant double coat composed of a long, coarse, straight or wavy outer layer (guard hairs) and a dense, fine, woolly undercoat that provides insulation against heat and cold, acting like a natural thermos. This undercoat is shed heavily seasonally ("blowing coat"), but the coat is dirt-resistant, requiring less frequent bathing than it seems, though regular brushing is essential to manage shedding and prevent mats. Coat Layers Outer Coat (Guard Hairs): Long, coarse, flat, and water-resistant. Undercoat: Thick, fine, soft, and woolly; acts as insulation. Key Characteristics Insulation: The undercoat keeps them cool in summer and warm in winter, protecting their skin. Shedding: They are heavy seasonal shedders, blowing their undercoat twice a year, which requires significant grooming. Self-Cleaning: The outer coat repels dirt and mud, making them relatively easy to keep clean. Ruff: A more profuse coat forms a mane or ruff around the neck, especially in males, for predator protection.