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Chilblains arise when skin is exposed to cold and the small vessels just beneath the surface are injured by freezing temperatures. The injury is a direct cold-induced damage to tissue, similar in concept to frostbite, which sets off inflammation, leakage of fluid from vessels, and the characteristic red, swollen lesions after rewarming. Among the options, the mechanism described as direct tissue freezing causing frostbite best fits this cold-injury process, because it centers on physical tissue damage from cold rather than infection or chemical burns. While vasoconstriction and impaired perfusion play a role in the development, the defining factor is that cold causes actual freezing injury to skin tissues and vessels, triggering the subsequent inflammatory response.